2 1/8 cups flour 1/2 tsp salt 1/2 tsp baking soda 12 Tbsp butter (1 1/2 sticks), melted and cooled slightly 1 cup brown sugar 1/2 cup white sugar 1 large egg 1 large egg yolk 2 tsps vanilla extract 1 12oz bag M&M’s, divided Preheat the oven to 325 degrees. Grease a 9×13 pan and set aside. In... more