Stir ricotta cheese, mozzarella cheese, garlic, salt, and pepper in a bowl; set aside on counter to allow to come to room temperature.
Bring a pot of water to a boil; cook penne in boiling water until cooked through yet firm to the bite, about 11 minutes. Drain and transfer to a large mixing bowl.
While pasta cooks, place a skillet over medium heat. Crumble turkey into the skillet; cook and stir until turkey is completely browned. Drain and add to pasta.
Spread 2 tablespoons of spaghetti sauce into the bottom of a 13x9-inch baking dish; stir the rest of the spaghetti sauce into pasta and turkey mixture. Spoon about half of the pasta mixture into the baking dish; top with cheese mixture and spread into an even layer. Spread remaining pasta mixture over cheese layer. Cover with aluminum foil if desired.
Bake in the preheated oven until slightly brown on top, about 30 minutes.