1 cup (2 sticks) butter or margarine, room temperature
3/4 cup granulated sugar
3/4 cup packed brown sugar
1 teaspoon vanilla
1/3 cup skim milk
1/3 cup Mini M&M's
2 cups of Hershey's Milk Chocolate Chips
Beat butter and sugars and in large bowl with electric mixer on medium speed until light and fluffy. Add milk and vanilla. Stir in flour and salt and mix on low speed (or by hand) until incorporated. Stir in M&Ms.
Cover and chill dough for 1 hour.
When dough is firm enough to handle (it may help to lightly flour your hands), form dough into 1" balls and arrange on a baking sheet lined with waxed paper. Place sheets in freezer and let chill for 30 minutes.
Melt chocolate chips in microwave stirring every 30 seconds until it is completely melted. Using forks or a dipping tool, dip cookie balls into chocolate to cover. Tap fork on side of pan to remove any excess coating, and return to waxed paper-lined baking sheets. Chill until set. Store, chilled, in an airtight container for up to 1 week (though good luck making them last that long).