Heat oven to 375°F. In small bowl, place 1/2 cup of the dry cake mix; set aside. In medium bowl, stir together remaining 1 cup cake mix, the cookie mix, butter and egg until soft dough forms. Shape dough into 24 (1 1/2-inch) balls. Roll in reserved cake mix, coating completely. On ungreased cookie sheet, place balls 2 inches apart.