Preheat oven to 400 degrees and grease a 6-count donut pan.
In a large bowl, mix flour, baking powder, salt, granulated sugar, and brown sugar together.
Mix butter and peanut butter together in a separate bowl, and add to the dry ingredients.
In a separate bowl, mix milk, International Delight® REESE’S Peanut Butter Cup Creamer, sour cream, egg, and vanilla extract together. Add to the dry ingredients, and mix until just combined.
Add in peanut butter and melted butter, and mix until combined.
Spoon (or pipe) donut mixture into the donut pan (you will probably have enough batter to make 8 donuts).
Bake for 9-10 minutes, or until the donuts 'spring' back when touched.
Allow to cool for at least 5 minutes before removing from the pan.
For the glaze, mix cocoa powder and powdered sugar together. Add in heavy cream and International Delight® REESE’S Peanut Butter Cup Creamer, and stir until smooth (if the glaze is thicker than you prefer, add in more liquid; alternatively, if it's too thin, add in more powdered sugar).
Dunk each donut halfway into the glaze. Top with chopped peanuts, if desired.
Enjoy!