Preheat oven to 350 degrees Fahrenheit. In the bowl of an electric mixer, combine butter, peanut butter, sugars, vanilla, and egg. In a separate bowl, stir together flour, baking powder, baking soda and salt. Add dry mixture to wet and mix until combined.

Cover dough and refrigerate for one hour, or until dough is firm. Shape dough into 1 1/4? balls and place about 3? apart on ungreased cookie sheet. Bake 8-10 minutes. Cool 5 minutes on the sheet before removing to a cooling rack and allow to cool completely.

For the frosting/glaze: In the bowl of an electric mixer mix together butter, cocoa powder, vanilla, powdered sugar and milk. Add marshmallow creme and mix. If it's too runny add a little more powdered sugar. If not spreadable enough, add a little more milk. Add a spoonful of frosting onto each cookie, making sure not to overdo it as the frosting will spread as it sets.