Preheat oven to 375F. Preheat a skillet to medium heat. Add the pepperoni and cook for 5 minutes until slightly crisp and the fat has rendered. Set aside.

In a bowl, combine the cream cheese, mozzarella, garlic powder, and half the parmesan. Spread the mixture in a shallow baking dish (8x8 or smaller). Spread the tomato sauce over the cheese mixture, then sprinkle on the rest of the parmesan and the prepared pepperoni.

Bake the dip for 20-30 minutes until hot, bubbly, and browned on top. Serve with dippers, and eat immediately while hot. Enjoy!