Preheat oven to 350 degrees. Line 2 large baking sheets with parchment paper.

In the bowl of an electric mixer, combine peanut butter, sugars, and butter. Using the paddle attachment, beat until smooth and combined. Add eggs and vanilla and beat until smooth. With the mixer on stir, add oats and baking soda and stir until combined. (My mixer was really full at this point, so make sure to keep on low speed or you may end up with a peanut butter oatmeal splatter!). Stir in chocolate chips and M & Ms.

Drop cookies by the heaping Tablespoon onto the prepared baking sheets. Press down gently with the palm of your hand. Press additional M & Ms onto the surface of each cookie if desired.

Bake for 10 to 12 minutes or until cookies are puffed and barely golden. Remove from oven and allow to set up on the baking sheet for 5 minutes before removing. Always err on the side of under baking cookies. Even if they look a little "unset" in the middle, go ahead and take them out. They'll set up on the baking sheet. Store in an airtight container for up to a week.