In a large skillet over medium heat, brown ground beef with minced garlic until fully cooked, about 5-7 minutes.

Stir in marinara sauce and Italian seasoning, and let simmer for 10 minutes.

In a mixing bowl, combine ricotta cheese, mozzarella cheese, and Parmesan cheese. Season with salt and pepper until smooth and creamy.

Cook manicotti shells in a large pot of salted boiling water for about 6-8 minutes. Drain and cool.

Stuff each manicotti shell with cheese mixture using a piping bag.

Preheat oven to 350°F (175°C). Spread a layer of meat sauce in a baking dish, arrange stuffed shells, cover with remaining sauce, and sprinkle mozzarella cheese on top.

Bake covered with foil for 30 minutes, then uncover and bake for an additional 5-10 minutes until bubbly and golden.

Let rest for 10 minutes before slicing to serve.