Heat oven to 350°F. Lightly spray bottom and sides of 13x9-inch pan with cooking spray. In large bowl, stir cookie mix, oil and egg until soft dough forms. On ungreased cookie sheet, drop 3 tablespoonfuls of dough 2 inches apart to make 3 cookies. Bake 12 to 13 minutes or until set. Cool 2 minutes; remove from cookie sheet to wire rack. Cool completely, about 15 minutes.