1Heat oven to 375ºF. In large bowl, stir cookie mix, softened butter and egg until soft dough forms. Shape dough into 36 (1 1/4-inch) balls (about 1 tablespoon each); place in ungreased mini muffin cups.
2Bake 9 to 11 minutes or until edges are light golden brown. Immediately press indentation into each with end of wooden spoon. Cool completely in pan, about 30 minutes. Remove from pan to serving plate.
3Spoon frosting into resealable food-storage plastic bag. Cut 3/8 inch off corner of bag. Gently insert cut corner of bag into indentation in each cookie cup. Squeeze bag to fill opening, about 2 teaspoons per cookie cup. Decorate cookie cups with candies.