Combine oats, baking powder, baking soda, flour, salt, and cinnamon in medium bowl. Set aside.
Combine butter, sugar, brown sugar, and peanut butter in bowl of mixer until fully mixed, about three minutes at medium speed.
Add eggs, one at a time, mixing for 30 seconds after each addition.
Add vanilla extract.
Reduce mixer speed and add oat mixture. Mix just until combined.
Add ½ cup M&Ms and ½ cup chocolate chips.
Cover bowl with plastic wrap and let rest at room temperature for one hour.
Preheat oven to 350°F. Line a baking sheet with parchment paper.
Use ½ cup measuring cup to portion cookies and place on the lined baking sheet. Cover individual cookies with remaining M&M's.
Bake for 16-20 minutes or until edges are slightly golden brown. Remove from oven and let cool.