Preheat oven to 375°F. In Small Batter Bowl, combine pepperoni, cheese, mushrooms and pizza sauce.
Roll out pizza dough to 11 x 15-inch rectangle, using Baker's Roller. Cut 12 circles in dough using Cut-N-Seal.
Using Medium Scoop, place 1 scoop (2 tablespoons) pepperoni mixture in center of 6 circles, spreading slightly. Place second dough circle on top. Lightly seal edges with fingers; seal with Cut-N-Seal.
Place on flat Baking Stone. Bake 15-17 minutes or until light golden brown. Serve with additional warm pizza sauce, if desired.