Preheat and prep: Heat the oven to 375°F (190°C). Lightly grease a 9x13-inch baking dish with olive oil spray or butter.
Warm the sauce: In a saucepan, heat the marinara over medium heat with the garlic, Italian seasoning, and crushed red pepper flakes.
Simmer 5 minutes to bloom the flavors. Taste and season with salt and pepper.
Make the “million dollar” cheese layer: In a bowl, mix ricotta, cream cheese, sour cream, 1 cup mozzarella, and 1/4 cup Parmesan until smooth. Season with a pinch of salt and pepper.
Par-cook meatballs if needed: If using frozen meatballs, follow package instructions to thaw or bake 10–12 minutes to take the chill off.
Homemade, fully cooked meatballs can go straight in.
Layer the dish: Spoon a thin layer of marinara into the baking dish. Add meatballs in an even layer. If using pasta, mix it with some sauce first, then nestle it among the meatballs.
Add the cheese blend: Dollop the ricotta mixture over the meatballs in big spoonfuls, then gently spread so it covers most of the surface.
It doesn’t need to be perfect.
Top with sauce and cheese: Pour the remaining marinara over the top. Sprinkle the remaining 1 cup mozzarella and 1/4 cup Parmesan evenly.
Bake: Cover loosely with foil and bake for 20 minutes. Remove the foil and bake another 10–15 minutes, until the cheese is melted, bubbly, and lightly golden around the edges.
Rest and garnish: Let it sit 5–10 minutes so the layers set.
Sprinkle with chopped basil or parsley before serving.
Serve: Spoon into bowls or over garlic bread. A simple green salad on the side balances the richness.