Preheat oven to 350 degrees F. Line a cookie sheet with parchment paper.

In a small bowl, combine flour, baking powder, baking soda, salt and stir with a whisk then set aside. In a large bowl fitted with a mixer, beat together the butter and sugar until smooth and fluffy. Beat in egg, vanilla extract, sour cream and milk/cream. Slowly add dry ingredients. Using a spatula, stir in mini M&M's. Using a cookie scoop, scoop dough and roll into balls then roll in sugar and place on cookie sheet. If you don't have a cookie scoop, form 1 inch balls then roll in sugar. Dough can be refrigerated, if desired. Bake 9 to 12 minutes in the oven. Allow to cool before removing. Allow baking sheet to completely cool before placing cookie dough on sheet to prevent spreading. If this happens, place cookie dough in fridge.