Heat oven to 350 degrees F.
Combine sugar, butter, and peanut butter in large bowl. Beat at medium speed, scraping bowl often, until well mixed (1 to 2 minutes).
Add eggs and vanilla; beat until well mixed (1 to 2 minutes).
Reduce speed to low; add flour, baking powder and baking soda. Beat until well mixed (1 to 2 minutes).
Stir in oats, m&ms and chips by hand.
Drop dough by heaping teaspoons into paper-lined mini muffin pans. Bake for 15 to 17 minutes or until set and light golden brown.
Let stand 2 minutes; remove from pans.
Note: When I put my paper liners into the mini muffin pans they kind of crumpled up, so I used regular muffin pans with the mini liners and they seemed to make a prettier cookie.