Preheat oven to 350 degrees, Insert 24 cupcake liners into a regular size cupcake pan. Set aside and make cupcake batter next.
In a large mixing bowl on medium speed,cream together the butter, peanut butter and brown sugar until fluffy (about 3-5 mins.) Add eggs one at a time. Beat well after each. Add vanilla.
In a separate bowl sift together the flour, baking powder, and salt. Gradually add to the creamed mixture, alternating with the milk. Mix well.
Fill cupcake liners 2/3 full with batter. Bake for 15-18 mins. or until toothpick inserted in center comes out clean. DO NOT OVER BAKE! Remove from oven and cool in the pans.
Once the cupcakes are cooled cut a quarter size or lit smaller hole in the center of the cupcake. Set that "cake cap" to the side. Fill with 1-2 tsp. jelly and replace the cake cap back on top. Decorating with peanut butter frosting and garnish with a small amount of jelly and a mini Nutter Butter cookie.
FROSTING: using a mixer beat together all ingredients except cookies until nice and smooth & fluffy. Pipe frosting onto cupcake and garnish with a small amount of jelly and a mini Nutter Butter cookie.