I wanted to make a cake that my Grandfather, a big fan of peanut butter cups, would enjoy so I whipped up some chocolate peanut butter frosting. This recipe only makes just enough to spread on the top of an 8x8" cake so if you want to frost the sides or are making a larger cake you will want to at least double it. Because of the peanut butter this won't be as light in texture or get as stiff on the outside as most frosting.
3 TBSP smooth style peanut butter
1 tsp vanilla
1 cup powdered sugar *
3 TBSP vanilla or plain almond milk
1 TBSP cocoa powder
Combine the ingredients in a mixing bowl and cream together with a fork or spoon. It may help to add 1/2 the sugar and stir it in before adding the second half. You can use a hand mixer or stand mixed instead if you like.
* If you are concerned about finding powdered sugar that was definitely not processed with bone char you can order it on Amazon or try a natural foods shop or Whole Foods.
NOTE: I use gluten free/alcohol free vanilla and smooth "natural" peanut butter with a tiny bit of palm oil in it. I don't know if using alcohol-based vanilla or true natural peanut butter (ie peanuts & salt) will alter the texture or flavor of the frosting.