Heat a skillet over medium heat. Add the ground beef and cook, breaking it apart, until fully browned. Drain any excess fat.

Stir the pasta sauce, garlic powder, and Italian seasoning into the skillet with the cooked meat. Bring to a gentle simmer and cook for 4 to 5 minutes so the flavors meld. Turn off the heat.

Spray the inside of the slow cooker with cooking spray. Spread a thin layer of the meat sauce across the bottom.

Arrange half of the frozen ravioli in a single layer over the sauce. Try to avoid overlapping too much.

Spoon half of the remaining meat sauce over the ravioli. Sprinkle half of the mozzarella, half of the cheddar, and half of the Parmesan on top.

Add another layer with the remaining ravioli. Cover with the rest of the meat sauce, then top with the remaining mozzarella, cheddar, and Parmesan.

Cover and cook on low for 4 to 5 hours. The ravioli should be hot through and the cheese fully melted.

Remove the lid and let the dish rest for 5 to 10 minutes before serving.