Preheat oven to 375°. Beat butter, shortening, sugars, vanilla and eggs in large bowl with medium speed. Stir in flour, baking soda and salt (dough will be stiff). Stir in chocolate chips and M&Ms. Drop dough by level teaspoonfuls or cookie/ice cream scoop about 2 inches apart onto ungreased cookie sheet. Bake 10-11 minutes or until light brown (center will be soft). Cool 1-2 minutes and then remove from cookie sheet to wire rack.