Preheat your oven to 350 degrees F.
In a large skillet, heat olive oil over medium heat. Add ground beef and Italian sausage, cooking until browned.
Add chopped onion and minced garlic to the skillet, sautéing until fragrant and onions are translucent.
Stir in marinara sauce and tomato sauce, seasoning with salt and pepper. Let simmer for about 10 minutes.
Cook rigatoni pasta according to package directions until al dente, then drain. Combine with meat sauce.
In a greased 9"x13" pan, layer half of the pasta mixture, top with half of the mozzarella cheese, then add remaining pasta and top with remaining cheese.
Cover with aluminum foil and bake for 30 minutes. Remove foil and bake for an additional 15-20 minutes until cheese is bubbly and golden brown.