Preheat and prep the dish. Heat your oven to 400°F (200°C). Lightly oil a 9x13-inch baking dish or similar casserole pan.

Par-cook the tortellini. Bring a large pot of salted water to a boil. Add tortellini and cook 2 minutes less than package directions (they’ll finish in the oven). Drain and set aside. If using frozen tortellini, cook just until they begin to float.

Sauté the aromatics. In a large skillet, warm olive oil over medium heat. Add garlic and cook 30–60 seconds until fragrant, not browned.

Build the sauce. Stir in marinara, heavy cream, Italian seasoning, and red pepper flakes. Simmer 2–3 minutes. Taste and season with salt and pepper. You want a rosy, slightly thick sauce that clings to pasta.

Combine pasta and sauce. Add the drained tortellini to the skillet and toss gently to coat. If your skillet is small, mix in a large bowl.

Layer the cheese. Spread half the sauced tortellini in the baking dish. Dollop half the ricotta over the top in small spoonfuls. Sprinkle with half the mozzarella and a dusting of Parmesan. Repeat with remaining tortellini, ricotta, mozzarella, and more Parmesan.

Bake until bubbly. Cover loosely with foil (tent so it doesn’t stick to cheese) and bake 15 minutes. Remove foil and bake another 8–10 minutes, until the top is golden and melty.

Rest and garnish. Let it stand 5 minutes so everything sets. Shower with chopped basil or parsley and a final pinch of Parmesan.

Serve. Spoon into warm bowls. Add cracked black pepper, a drizzle of olive oil, or a few chili flakes if you like heat.