Preheat oven to 350 degrees

Line a baking sheet with parchment paper

In a large bowl using a hand mixer, cream butter, shortening, sugar and brown sugar

Once combined, add vanilla and eggs

In a separate bowl, mix flour, baking soda and salt

Combine dry ingredient mixture into wet ingredient mixture and gently fold in M&M's

Place tablespoon sized drops of mixture onto lined cookie sheet

Bake 10 minutes, or until the edges are lightly browned

Cool on wire rack & enjoy!