In a large skillet, cook turkey over medium heat until no longer pink; drain any excess grease. Sprinkle with garlic powder, salt, and pepper, then set aside.
Meanwhile, peel and grate carrots and chop mushrooms.
In a large saucepan, cook carrots and mushrooms in oil until tender. Stir in marinara sauce.
Spread 1/2 cup sauce in a greased 9 x 13-inch baking dish.
Layer with half of each: ravioli, sauce mixture, turkey, and cheeses. Repeat layers, then sprinkle with chopped basil.
Cover with foil and bake for 25-30 minutes, then uncover and bake 10 minutes longer until bubbly.