In a skillet over medium heat, cook ground beef with chopped onion until fully browned.
Add garlic and cook for 1 more minute. Drain excess grease.
Stir in marinara sauce and Italian seasoning. Season with salt and pepper.
Simmer for 5 minutes, then remove from heat.
Prepare the Ricotta Mixture
In a medium bowl, mix ricotta cheese and sour cream until smooth.
Layer the Casserole
In the prepared baking dish, layer as follows:
Half of the frozen ravioli
Half of the ricotta mixture
Half of the meat sauce
Sprinkle of mozzarella cheese
Repeat the layers with the remaining ravioli, ricotta mixture, meat sauce, and mozzarella.
Top & Bake
