Preheat your oven to 375°F (190°C). Grease a 9x13-inch baking dish lightly with cooking spray. You’ll thank yourself later for not having to scrub baked-on cheese off the dish!

Bring a large pot of salted water to a boil. Cook the tortellini according to the package instructions, but shave a minute or two off the cooking time since they’ll continue to cook in the oven. Drain and set aside. It’s all about achieving that perfect al dente texture.

In a medium bowl, combine the ricotta cheese, sour cream, half of the shredded mozzarella, Parmesan cheese, garlic powder, Italian seasoning, and red pepper flakes (if using). Stir until well blended. This filling is the heart of the dish, so don’t skimp on the mixing—it’s worth the effort to ensure every bite is flavorful.

Spread about 1/2 cup of marinara sauce on the bottom of the prepared baking dish. Layer half of the cooked tortellini on top. Spoon half of the cheesy filling over the tortellini and spread it out evenly. Add another 1/2 cup of marinara sauce, followed by the remaining tortellini and cheesy filling. Finish with the remaining marinara sauce and sprinkle the top with the rest of the shredded mozzarella. Trust me, the layering process might seem tedious, but it’s where the magic happens.

Cover the baking dish with foil and bake for 20 minutes. Then, remove the foil and bake for another 10 minutes, or until the cheese is bubbly and slightly golden. The aroma wafting through your kitchen at this point is pure bliss.

Let the casserole cool for 5 minutes before serving. Sprinkle with fresh parsley for a pop of color and extra flavor. That little touch of green makes it feel fancy—like you’re eating at a chic Italian bistro.