Most Awesome M&M Cookies of All Time

I have never tasted M&M cookies this delicious before.  I'm sad that I've given all but a few of them away.  Must make more ASAP.  Thanks to How Sweet Eats for this one!

Ingredients

• 2 cups + 2 tablespoons all-purpose flour
• 1/2 teaspoon baking soda
• 1 1/2 sticks (12 tablespoons) salted butter, melted and cooled
• 1 cup brown sugar
• 1/2 cup sugar
• 1 egg + 1 egg yolk, room temperature
• 2 teaspoons vanilla extract
• 1 cup mini M&Ms

Directions

1. Preheat oven to 325°.  Mix the flour and baking soda in a bowl and set aside.  In another bowl, mix the butter and sugars until they are combined.  Add the egg, egg yolk, and vanilla and stir until mixed.  Gradually add flour mixture until dough forms.  It will look crumbly at first, but it will come together.  Fold in the M&Ms.
2. Shape dough into tablespoon-sized balls and tear each ball in half.  Stack the halves on top of each other (first half flat side down, second half round side down) so they look like this.  Place 2 inches apart on cookie sheets.
3. Bake 8-12 minutes or until the edges are slightly brown.  The centers should be soft and puffy.  Do not over bake.  Let sit on cookie sheet 2 minutes, then transfer to wire rack and cool completely.