Let’s create this beautiful blueberry frosting:

1. Make the Blueberry Sauce:

• Combine the fresh blueberries, granulated sugar, cornstarch, and lemon zest in a medium saucepan.
• Place the saucepan over medium heat. Cook the mixture, stirring frequently with a whisk or spatula, bringing it to a gentle simmer.
• As the blueberries heat up, gently smash some of them against the side of the pan with your spoon/spatula to release their juices.
• Continue to cook and stir until the sauce visibly thickens (enough to coat the back of a spoon) and the liquid looks slightly translucent (indicating the cornstarch is cooked), about 5-8 minutes from when it starts simmering.
• Remove the sauce from the heat. (Optional: For a smoother sauce, press it through a fine-mesh sieve to remove skins/seeds).

2. Cool Blueberry Sauce COMPLETELY:

• Transfer the blueberry sauce to a heatproof bowl. Allow it to cool completely to room temperature. To cool it faster, place the bowl over an ice bath and stir occasionally. Do NOT add hot or warm sauce to the cream cheese mixture.

3. Make the Cream Cheese Frosting Base:

• In a large bowl (or the bowl of a stand mixer with the paddle attachment), place the softened cream cheese and room temperature butter.
• Beat together on medium-high speed until completely smooth, creamy, and well combined, scraping down the sides of the bowl as needed. There should be no lumps.
• Add the sifted powdered sugar, vanilla extract, and pinch of salt. Start mixing on low speed until the sugar is mostly incorporated (to avoid a sugar cloud), then increase to medium-high speed.
• Beat for another 2-3 minutes until the frosting is light, smooth, and fluffy.

4. Combine Sauce and Frosting:

• Add the completely cooled blueberry sauce to the cream cheese frosting base.
• Using a rubber spatula, gently fold the blueberry sauce into the frosting. You can fold minimally for distinct streaks and chunks of blueberry, or fold more thoroughly until the frosting is uniformly purple and smoother (though some small fruit pieces may remain). Avoid vigorous mixing with the electric mixer at this stage, which can deflate the frosting or cause issues.

5. Chill if Necessary:

• Assess the frosting’s consistency. If it seems too soft for your intended use (especially for piping), cover the bowl and chill the finished frosting in the refrigerator for 20-30 minutes to firm up slightly.

6. Use:

• Spread or pipe the Fresh Blueberry Cream Cheese Frosting onto your completely cooled favorite cakes or cupcakes!

Patience while cooling the sauce is crucial!