Let’s assemble and bake this delicious spaghetti casserole:

1. Preheat Oven and Prepare Dish & Pasta:

• Preheat your oven to 350°F (175°C).
• Lightly grease a 9×13-inch baking dish with non-stick spray or butter.
• Bring a large pot of lightly salted water to a rolling boil. Cook the spaghetti in the boiling water, stirring occasionally, until it’s tender yet still firm to the bite (al dente), usually about 10-12 minutes. Drain the pasta well.

2. Make the Meat Sauce:

• While the pasta cooks, heat a large skillet over medium heat.
• Add the ground beef and chopped onion to the hot skillet. Cook, stirring and breaking up the meat, until the beef is thoroughly browned and the onion is soft and translucent, about 5 to 7 minutes.
• Carefully drain off any excess grease from the skillet.
• Stir in the jarred meatless spaghetti sauce and the seasoned salt. Bring to a simmer and cook for a few minutes for flavors to meld, then remove from heat.

3. Prepare Spaghetti Base:

• In a large mixing bowl, whisk together the beaten eggs, grated Parmesan cheese, and melted butter until well combined.
• Add the drained, cooked spaghetti to the egg mixture. Toss gently but thoroughly until the spaghetti is evenly coated.

4. Assemble the Casserole Layers:

• First Spaghetti Layer: Spread half of the spaghetti mixture evenly into the bottom of the prepared baking dish.
• First Cheese & Sauce Layer: Top the spaghetti with half of the cottage cheese (1 cup), spreading it as evenly as possible. Sprinkle 2 cups of the shredded mozzarella cheese over the cottage cheese. Spoon half of the prepared meat sauce over the mozzarella layer.
• Repeat Layers: Carefully arrange the remaining spaghetti mixture over the meat sauce. Top with the remaining cottage cheese (1 cup), another 2 cups of shredded mozzarella cheese, and finally, the remaining meat sauce.

5. Bake (Stage 1 – Covered):

• Cover the baking dish tightly with aluminum foil.
• Place the covered casserole in the preheated oven. Bake for 40 minutes.

6. Bake (Stage 2 – Uncovered with Final Cheese):

• After 40 minutes, carefully remove the aluminum foil from the baking dish.
• Sprinkle the remaining 1 cup of shredded mozzarella cheese evenly over the top of the casserole.
• Return the dish to the oven, uncovered. Continue to bake for an additional 20 to 25 minutes. The casserole is done when the cheese on top is melted, bubbly, and lightly golden brown, and the casserole is heated through.

7. Rest Before Serving (Important!):

• Carefully remove the hot Baked Spaghetti from the oven. Let it rest on a wire rack for at least 10-15 minutes before slicing and serving. This crucial resting period allows the layers to set, making it much easier to cut into neat slices and preventing it from being too soupy.

8. Serve:

• After resting, slice into squares and serve hot. Garnish with fresh parsley or basil if desired.

A hearty, cheesy, comforting casserole ready to be devoured