Introduction & Inspiration
If you’re a die-hard fan of the iconic chocolate and peanut butter combination, especially in the form of Reese’s Peanut Butter Cups, then prepare yourself for an absolutely irresistible treat! This recipe for Reese’s Peanut Butter Cup Brownies takes a classic fudgy brownie base, embeds whole Reese’s Cups within it, and then crowns it all with a luscious, creamy peanut butter frosting. It’s a triple threat of chocolate and peanut butter goodness that immediately had me drooling!
My inspiration came from wanting to create the ultimate brownie experience for peanut butter lovers. Brownies are fantastic on their own, but adding a surprise layer of Reese’s Cups and a rich peanut butter frosting elevates them to a whole new level of decadence. Using a boxed brownie mix makes the base incredibly easy, allowing more focus on the fun additions.
My goal is to guide you through making these show-stopping brownies. We’ll cover how to easily incorporate the candy, whip up the simple yet divine peanut butter frosting, and create a dessert bar that’s guaranteed to be the star of any party, bake sale, or indulgent night in.
Let’s get ready to bake (and frost!) some serious chocolate peanut butter magic!
Nostalgic Appeal / Comfort Food Connection
These Reese’s Peanut Butter Cup Brownies are a powerhouse of nostalgic comfort food appeal! Brownies themselves are a quintessential American treat, evoking memories of childhood bake sales, after-school snacks, and simple, satisfying chocolate indulgence. Their fudgy texture and rich chocolate flavor are universally loved.
Reese’s Peanut Butter Cups are another iconic candy, a beloved favorite for generations, known for that perfect marriage of milk chocolate and salty, creamy peanut butter filling. The mere sight of those orange wrappers brings a smile to many faces.
This recipe brilliantly combines these two nostalgic giants. It offers the comforting familiarity of a warm brownie, but with the exciting surprise of whole peanut butter cups baked inside and a frosting that echoes that beloved candy flavor. It’s pure, unadulterated comfort and joy.
Making and eating these brownies feels like indulging in the ultimate chocolate peanut butter fantasy – a decadent, fun, and incredibly satisfying treat.
Homemade Focus (Easy Base, Decadent Additions)
While this recipe cleverly starts with a convenient boxed brownie mix, the real homemade magic comes from the thoughtful additions and the from-scratch peanut butter frosting. This approach delivers a semi-homemade dessert that tastes incredibly special and indulgent with relatively little fuss.
I love recipes that show how to elevate simple bases. Here, you’re taking a standard brownie mix and transforming it by layering whole Reese’s Peanut Butter Cups right into the batter before baking. This simple homemade step creates a delightful surprise and an extra layer of flavor and texture.
The peanut butter frosting is another key homemade component. You’re whipping together softened butter, creamy peanut butter, powdered sugar, heavy cream, and vanilla to create a rich, fluffy, and intensely flavorful frosting that’s far superior to any store-bought alternative.
From carefully arranging the Reese’s Cups to whipping the luscious frosting and adding final garnishes, the process emphasizes creating a truly decadent, multi-layered brownie experience with smart homemade touches.
Flavor Goal
The primary flavor goal of these Reese’s Peanut Butter Cup Brownies is an intense, decadent explosion of chocolate and peanut butter flavors with a variety of textures. It aims for a fudgy chocolate brownie base, pockets of creamy peanut butter and milk chocolate from the baked-in Reese’s Cups, and a rich, smooth, salty-sweet peanut butter frosting.
The brownie layer provides a deep, moist, fudgy chocolate foundation.
The embedded Reese’s Peanut Butter Cups soften during baking, creating gooey pockets of their signature milk chocolate and creamy peanut butter filling.
The peanut butter buttercream frosting offers a rich, sweet, and slightly salty peanut butter flavor with a light, fluffy texture.
Optional toppings like more chopped Reese’s Cups or a chocolate drizzle add further layers of texture and reinforce the core chocolate and peanut butter theme. The overall effect is pure chocolate-peanut butter paradise in bar form.
Ingredient Insights
Let’s explore the key ingredients for this indulgent treat:
For the Brownies:
- Box brownie mix (18 oz): The convenient base. Choose a fudgy style for best results. Prepare according to package instructions (typically requiring eggs, oil, water).
- Full-size Reese’s Peanut Butter Cups: The star surprise! Layered in the middle of the brownie batter. About 15 cups fit well in a 9×13 pan.
For the Peanut Butter Frosting:
- Creamy peanut butter: Provides the dominant peanut butter flavor. Standard commercial creamy (like Jif or Skippy) works best for smooth frosting.
- Unsalted butter, room temperature: Creates a rich, creamy buttercream base. Must be properly softened.
- Confectioners’ sugar (powdered sugar): Sweetens and provides structure. Sifting is recommended for a lump-free frosting.
- Heavy cream: Adds moisture and helps create a light, fluffy, spreadable consistency. Milk can substitute but might result in a slightly less rich frosting.
- Vanilla extract: Enhances the peanut butter and sweet flavors.
- (Optional: Pinch of salt if using unsalted butter/peanut butter, to balance sweetness)
Optional Toppings:
- Mini chocolate chips or Crushed peanut butter cups: For extra texture and flavor.
- Chocolate drizzle.
Using good quality peanut butter and ensuring butter/cream cheese (oops, no cream cheese here, just butter for frosting!) are at room temperature are key.
Essential Equipment
You’ll need standard baking and frosting tools:
- A 9×13-inch baking pan: The standard size for baking the brownies.
- Parchment paper: Highly recommended for lining the pan, creating a sling for easy removal of the cooled brownies.
- Mixing bowls: One large for brownie batter (as per mix), one medium/large for the frosting.
- An Electric mixer (handheld or stand mixer with paddle attachment): Essential for making the peanut butter buttercream frosting smooth and fluffy.
- A Rubber spatula: For scraping bowls and spreading batter/frosting.
- Measuring cups and spoons.
- An Offset spatula or knife: For spreading frosting evenly.
Lining the pan with parchment makes removing and cutting the brownies much easier.
List of Ingredients with Measurements
Here’s the complete list of ingredients, with precise measurements:
For the Brownies:
- 1 (18 ounce) box brownie mix (plus ingredients called for on its box – typically eggs, oil, water)
- 15 full-size Reese’s Peanut Butter Cups
For the Frosting:
- ¾ cup creamy peanut butter
- ½ cup (1 stick) unsalted butter, room temperature
- 2 ¼ cups confectioners’ sugar, sifted
- 4 Tablespoons heavy cream (or milk)
- 1 ½ teaspoons vanilla extract
- (Optional: Pinch of salt)
Optional Toppings:
- ½ cup mini chocolate chips or crushed peanut butter cups
- Chocolate drizzle
These quantities are perfect for a rich 9×13 pan of brownies.
Ensure butter for frosting is at room temperature.

Step-by-Step Instructions (Brownies, Reese’s & Frosting!)
Let’s bake and assemble these decadent brownies:
1. Preheat Oven and Prepare Pan:
- Preheat your oven to 350°F (175°C), or as directed on your brownie mix package.
- Line a 9×13-inch baking pan with parchment paper, leaving an overhang on two opposite sides to act as handles. Lightly grease the parchment if desired, though usually not necessary with brownies. Set aside.
2. Prepare and Layer Brownie Batter with Reese’s Cups:
- Prepare the brownie mix batter according to the package instructions, using the ingredients (eggs, oil, water) listed on the box.
- Spread about ⅔ of the prepared brownie batter evenly into the bottom of the lined baking pan.
- Arrange the 15 full-size Reese’s Peanut Butter Cups in a single layer over the batter, pressing them in slightly. Space them out evenly.
- Gently spread the remaining ⅓ of the brownie batter over the Reese’s Cups, ensuring they are as fully covered as possible. Spread carefully so as not to displace the candies too much.
3. Bake the Brownies:
- Place the pan in the preheated oven.
- Bake for 25-30 minutes, or until a wooden toothpick inserted into the brownie portion (avoiding a melted Reese’s Cup) near the center comes out with a few moist crumbs attached, but not wet batter. Be careful not to overbake, as this will result in dry brownies.
- If wet batter remains after 30 minutes, bake for a few minutes longer, checking frequently.
4. Cool Brownies Completely:
- Remove the brownies from the oven and place the pan on a wire rack.
- Let the brownies cool completely in the pan. This is crucial and may take 2-3 hours. Do not attempt to frost warm brownies, as the frosting will melt.
5. Make the Peanut Butter Frosting:
- While the brownies cool (or once they are fully cool), prepare the frosting. In a large bowl, beat the room temperature creamy peanut butter and softened unsalted butter together with an electric mixer (handheld or stand mixer) on medium speed until smooth and well combined.
- Gradually mix in the sifted confectioners’ sugar on low speed until incorporated. Scrape down the sides of the bowl as needed. The mixture will be thick at this point.
- Add the heavy cream and vanilla extract. Mix on low speed until combined, then increase the speed to medium-high and whip for about 2 minutes, until the frosting is light, fluffy, and spreadable. If too thick, add a tiny bit more cream; if too thin, add a little more sifted powdered sugar.
6. Frost and Finish the Brownies:
- Once the brownies are completely cool, use the parchment paper overhang to carefully lift them out of the pan and place them on a cutting board.
- Spread the prepared peanut butter frosting evenly over the top of the cooled brownies.
- Sprinkle with optional mini chocolate chips or crushed peanut butter cups. Add an optional chocolate drizzle if desired.
7. Chill (Optional but Recommended) and Serve:
- For the neatest slices and best texture, chill the frosted brownies in the refrigerator for at least 30 minutes to 1 hour to allow the frosting to set.
- Slice into squares and serve. Enjoy!
Patience during cooling is key for frosting and slicing!
Troubleshooting
Brownies with fillings and frosting can have a few potential issues:
- Problem: Brownies are dry or cakey.
- Solution: Choose a fudgy brownie mix. Don’t overbake! Check for doneness with a toothpick in the brownie part, not the melted candy. Box mixes usually have reliable bake times.
- Problem: Reese’s Cups sank completely or melted out.
- Solution: Pressing them in slightly helps. Ensuring a decent layer of batter underneath and completely covering them on top also helps. Some melting and melding is normal and delicious!
- Problem: Frosting is greasy or separated.
- Solution: Butter was likely too warm. Ensure it’s properly softened to room temperature, not melty. Try chilling the frosting briefly (10-15 mins) and re-whipping. Using standard commercial creamy peanut butter helps stability.
- Problem: Frosting is too thick or thin.
- Solution: Adjust consistency carefully with small additions of heavy cream (to thin) or more sifted powdered sugar (to thicken).
- Problem: Difficult to slice neatly.
- Solution: Cool brownies completely before frosting. Chill frosted brownies for at least 30-60 minutes before slicing. Use a large, sharp knife, and wipe it clean with a hot, damp cloth between cuts.
Cooling is crucial for both frosting and slicing!
Tips and Variations
Let’s customize these ultimate chocolate peanut butter treats:
- Tip: Use your favorite fudgy brownie mix for the best base texture.
- Variation: Instead of full-size Reese’s Cups, use mini Reese’s Cups (you’ll need more) scattered throughout the batter or just in the middle layer.
- Tip: For easier spreading of the top layer of brownie batter over the Reese’s Cups, drop small spoonfuls all over, then gently connect and spread.
- Variation: Add ½ cup of chopped peanuts or chocolate chips to the brownie batter for extra texture.
- Tip: Ensure butter for frosting is perfectly at room temperature – soft enough to indent easily with a finger, but not greasy or melted.
- Variation: Use different candies in the middle layer, like chopped Snickers, Twix, or Rolos (caramel might ooze more).
- Variation: Make a chocolate peanut butter frosting by adding 1/4 cup of unsweetened cocoa powder (sifted) to the peanut butter frosting ingredients.
Endless ways to make them even more decadent!
Serving and Pairing Suggestions
These Reese’s Peanut Butter Cup Brownies are incredibly rich and satisfying.
Serving: Serve at room temperature or slightly chilled, cut into squares.
Pairing:
- The Classic: A tall glass of cold milk is the absolute perfect accompaniment!
- Coffee/Tea: Great with a cup of coffee or tea for an afternoon treat.
- A La Mode: Serve a slightly warmed brownie square with a scoop of vanilla bean or chocolate ice cream for an over-the-top dessert.
- Parties/Bake Sales: These are guaranteed to be a huge hit at any gathering or bake sale. Cut into smaller squares for easier sharing.
A little square goes a long way due to their richness!
Nutritional Information
These are extremely indulgent brownies, packed with chocolate, peanut butter, candy, and frosting. Nutritional info is highly approximate (per brownie, assuming 16-20 brownies from a 9×13 pan):
- Calories: 350-500+
- Fat: 20-30+ grams
- Saturated Fat: 8-15+ grams (High from butter, brownie mix fats, Reese’s, frosting)
- Cholesterol: 30-50+ mg
- Sodium: 150-250+ mg
- Total Carbs.: 40-60+ grams
- Dietary Fiber: 2-4 grams
- Sugars: 30-45+ grams (Very high)
- Protein: 4-7 grams
Definitely a special occasion treat, very high in sugar and fat. Enjoy mindfully!
PrintReese’s Peanut Butter Cup Brownies
Bake decadent Reese’s Peanut Butter Cup Brownies! Features a fudgy brownie with whole Reese’s Cups baked inside, topped with creamy peanut butter frosting.
Ingredients
Here’s the complete list of ingredients, with precise measurements:
For the Brownies:
- 1 (18 ounce) box brownie mix (plus ingredients called for on its box – typically eggs, oil, water)
- 15 full-size Reese’s Peanut Butter Cups
For the Frosting:
- ¾ cup creamy peanut butter
- ½ cup (1 stick) unsalted butter, room temperature
- 2 ¼ cups confectioners’ sugar, sifted
- 4 Tablespoons heavy cream (or milk)
- 1 ½ teaspoons vanilla extract
- (Optional: Pinch of salt)
Optional Toppings:
- ½ cup mini chocolate chips or crushed peanut butter cups
- Chocolate drizzle
These quantities are perfect for a rich 9×13 pan of brownies.
Ensure butter for frosting is at room temperature.
Instructions
Let’s bake and assemble these decadent brownies:
1. Preheat Oven and Prepare Pan:
- Preheat your oven to 350°F (175°C), or as directed on your brownie mix package.
- Line a 9×13-inch baking pan with parchment paper, leaving an overhang on two opposite sides to act as handles. Lightly grease the parchment if desired, though usually not necessary with brownies. Set aside.
2. Prepare and Layer Brownie Batter with Reese’s Cups:
- Prepare the brownie mix batter according to the package instructions, using the ingredients (eggs, oil, water) listed on the box.
- Spread about ⅔ of the prepared brownie batter evenly into the bottom of the lined baking pan.
- Arrange the 15 full-size Reese’s Peanut Butter Cups in a single layer over the batter, pressing them in slightly. Space them out evenly.
- Gently spread the remaining ⅓ of the brownie batter over the Reese’s Cups, ensuring they are as fully covered as possible. Spread carefully so as not to displace the candies too much.
3. Bake the Brownies:
- Place the pan in the preheated oven.
- Bake for 25-30 minutes, or until a wooden toothpick inserted into the brownie portion (avoiding a melted Reese’s Cup) near the center comes out with a few moist crumbs attached, but not wet batter. Be careful not to overbake, as this will result in dry brownies.
- If wet batter remains after 30 minutes, bake for a few minutes longer, checking frequently.
4. Cool Brownies Completely:
- Remove the brownies from the oven and place the pan on a wire rack.
- Let the brownies cool completely in the pan. This is crucial and may take 2-3 hours. Do not attempt to frost warm brownies, as the frosting will melt.
5. Make the Peanut Butter Frosting:
- While the brownies cool (or once they are fully cool), prepare the frosting. In a large bowl, beat the room temperature creamy peanut butter and softened unsalted butter together with an electric mixer (handheld or stand mixer) on medium speed until smooth and well combined.
- Gradually mix in the sifted confectioners’ sugar on low speed until incorporated. Scrape down the sides of the bowl as needed. The mixture will be thick at this point.
- Add the heavy cream and vanilla extract. Mix on low speed until combined, then increase the speed to medium-high and whip for about 2 minutes, until the frosting is light, fluffy, and spreadable. If too thick, add a tiny bit more cream; if too thin, add a little more sifted powdered sugar.
6. Frost and Finish the Brownies:
- Once the brownies are completely cool, use the parchment paper overhang to carefully lift them out of the pan and place them on a cutting board.
- Spread the prepared peanut butter frosting evenly over the top of the cooled brownies.
- Sprinkle with optional mini chocolate chips or crushed peanut butter cups. Add an optional chocolate drizzle if desired.
7. Chill (Optional but Recommended) and Serve:
- For the neatest slices and best texture, chill the frosted brownies in the refrigerator for at least 30 minutes to 1 hour to allow the frosting to set.
- Slice into squares and serve. Enjoy!
Patience during cooling is key for frosting and slicing!
Recipe Summary and Q&A
Let’s conclude with a summary and common questions:
Recipe Summary:
Reese’s Peanut Butter Cup Brownies feature a fudgy brownie base (made from a box mix) with a layer of full-size Reese’s Peanut Butter Cups baked into the center. Once cooled completely, the brownies are topped with a rich, homemade creamy peanut butter buttercream frosting and optional garnishes like more chopped Reese’s or chocolate chips.
Q&A:
Q: Can I make these ahead of time? A: Yes! Bake the brownies and let them cool completely. They can be stored unfrosted, well-wrapped, at room temperature for a day. The frosting can also be made ahead and stored refrigerated (bring to room temp and re-whip before use). Frost the cooled brownies up to a day before serving.
Q: How do I store the frosted brownies? A: Store frosted brownies in an airtight container at room temperature for 2-3 days, or in the refrigerator for up to 5 days (though refrigeration can make brownies a bit firmer).
Q: Can I freeze these brownies? A: Yes, they freeze well, both frosted and unfrosted. Cool completely, slice if desired, then wrap tightly (individually or whole slab) in plastic wrap and then foil, or place in a freezer-safe container. Freeze for up to 3 months. Thaw at room temperature or in the refrigerator.
Q: Can I use homemade brownie batter? A: Absolutely! If you have a favorite fudgy 9×13 brownie recipe, feel free to use that as the base instead of a box mix.
Q: My Reese’s Cups all sank to the bottom. Why? A: Ensure you spread a decent layer (about 2/3 as suggested) of the brownie batter underneath the Reese’s Cups. Pressing them in only slightly helps. The batter should be thick enough to support them somewhat.
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