Preheat oven to 350 degrees. In a stand mixer, cream together softened butter, creamy peanut butter, and sugar. Add eggs and vanilla until combined.
Add in the flour, and baking powder until combined. Once combined, slowly add in the milk. Stir in the chocolate chips.
Fill the cupcake liner about 2/3 full. I was able to get about 12 cupcakes. Bake for about 20 minutes or until lightly brown and toothpick inserted comes out clean. Allow to cool completely.
To make the frosting, in a stand mixer blend together the cream cheese, peanut butter and butter until combined. Slowly add in powdered sugar, brown sugar, flour and vanilla. Add in the oats.
Stir in the M&M's and chocolate chips. Frost each cupcake with the frosting.