In a large mixing bowl, thoroughly combine the ricotta cheese, Italian seasoning, garlic powder, onion powder, and a pinch of salt and pepper. Stir until the mixture is smooth and well blended.
Generously spray the inside of your crockpot with cooking spray to prevent the lasagna from sticking.
Pour a thin layer of marinara sauce evenly over the bottom of the crockpot, ensuring a solid base for the layers to follow.
Place half of the refrigerated ravioli on top of the marinara sauce, distributing them as evenly as possible to cover the surface.
Carefully spoon half of the ricotta cheese mixture over the ravioli, using a spatula to spread it out evenly. Next, sprinkle 1 cup of shredded mozzarella cheese evenly across the ricotta layer, followed by 1/2 cup of grated Parmesan cheese.
Add another layer of marinara sauce over the cheese mixture, ensuring it covers the entire layer. Place the remaining ravioli on top of the sauce, again spreading them evenly.
Repeat the layering process by adding the remaining ricotta mixture on top of the last layer of ravioli, topping it with the rest of the marinara sauce, and finishing with the remaining mozzarella and Parmesan cheese sprinkled over the top.
Securely cover the crockpot with its lid and set it to cook on low for 4-5 hours or on high for 2-3 hours, until the cheese is melted, bubbly, and lightly golden.
Once cooked, turn off the crockpot and allow it to rest with the lid on for about 10 minutes. This resting time helps the layers to firm up slightly for easier serving.
If desired, garnish your ravioli lasagna with fresh basil leaves to add a pop of color and flavor before serving.
Notes
Serve directly from the crockpot for neat squares.