Preheat your oven to 375°F. In a large bowl, combine the ground beef, Italian sausage, garlic powder, onion powder, Italian seasoning, salt, and pepper. Mix until well combined and form into meatballs, about 1 inch in diameter.
Heat olive oil in a large skillet over medium heat. Add the meatballs and cook until browned on all sides, about 5-7.
In a 9x13 inch baking dish, spread half of the marinara sauce on the bottom. Place the browned meatballs in a single layer on top of the sauce. Pour the remaining marinara sauce over the meatballs.
Sprinkle the mozzarella and Parmesan cheese over the top of the meatballs and sauce. Bake for 25-30 until the cheese is bubbly and golden.