Preheat oven to 350 degrees.
Line a baking sheet with parchment paper,
Beat butter and sugars.
Add egg and vanilla.
Add peanut butter.
Add flour, baking soda and salt.
Fold in M&M's. Stir until just combined.
Divide into two portions and place one portion on cookie sheet. Decorate top with extra M & M's and chips as desired.
Bake 12- 14 mins and add more chips once removed from oven.
Serve warm with milk.