You'll Need: Cookie Sheets Parchment Paper Mini M&M's M and M S'mores Cookies Ingredients Ingredients: 12 T. salted butter, softened 3/4 c. dark brown sugar, packed 1/4 c. sugar 1 egg 2 tsp. vanilla 2 cups flour 2 tsp. cornstarch 1 tsp. baking soda pinch of salt 1 bag Mini M & M's Mini Marshmallows