Heat oven to 425°F. Grease 12-inch pizza pan with shortening or cooking spray. Unroll dough; place in pan. Starting at center, press out dough to edge of pan, pressing up and extending over sides by at least 1 inch. Place string cheese around inside edge of crust. Fold extended edge of dough over cheese; pinch firmly to seal.
Spoon sauce evenly over dough. Top with pepperoni and cheese blend.
Bake 12 to 16 minutes or until crust is deep golden brown and cheese in center is melted. Cut into wedges.