Preheat a waffle iron according to manufacturer's instructions.

Roll pizza dough to 1/2-inch thickness on a flat work surface. Cut dough into 16 rounds using a 2-inch cutter. Press rounds out with your fingers until each measures about 3 inches across.

Spoon 1 teaspoon pizza sauce into the center of 8 rounds. Top each with 2 teaspoons mozzarella cheese and 1 slice of pepperoni. Cover with remaining 8 rounds, pressing around edges to seal.

Cook the sealed rounds, in batches, on the preheated waffle iron until lightly browned, about 2 minutes. Top each one with another pepperoni slice and a little more mozzarella cheese. Close waffle iron and continue cooking until golden brown, 1 to 2 minutes more.