Preheat the oven to 450°F.
In a large bowl, mix 1 cup of mozzarella cheese, the Cheddar cheese, egg, garlic powder, salt, and pepper.
On a parchment-lined 16-inch pizza pan, spread the cheese dough evenly around the pan. The crust should be thin, but without any holes.
Place the pan in the oven. Bake the crust for 15 to 20 minutes, or until browned. Check the oven after 10 minutes to make sure it’s not burning.
Remove the crust from the oven. Turn the oven to broil.
With paper towels, blot any excess grease from the crust.
Spread the sauce over the crust. Top with the remaining 1⁄2 cup of mozzarella cheese and the pepperoni.
Return the pan to the oven. Bake for 3 to 4 minutes, or until the cheese is melted and bubbling.
Remove the pan from the oven. Cool the pizza for 3 to 5 minutes before slicing and serving.