Preheat the oven to 350 degrees Fahrenheit and line 2 cupcake tins with cupcake liners.

Crush the Butterfinger candy bars into small pieces.  Reserve some of the crushed candy bars for the topping and place the remaining in a large mixing bowl.

Stir in the eggs, vegetable oil, milk, sour cream and vanilla extract.  Mix until thoroughly combined.

Then add in the cake mix and stir until the mixture is smooth.

Fill the cupcake liners until they are approximately 3/4 of the way full.

Bake for 18-22 minutes until a toothpick inserted into the center of the cupcakes comes out clean.

Cool completely at room temperature.

In a medium bowl, cream together butter and peanut butter until smooth and fluffy.

Gradually add powdered sugar, alternating with milk, beating after each additional until desired consistency.

Pipe the frosting onto each of the cupcakes with Tip 1M (star decorating tip).

Top each of the cupcakes with the reserved crushed Butterfinger Candy Bars.

Cut the other candy bars into small pieces and place a piece on top of each of the cupcakes.

Then the cupcakes are ready to serve and enjoy!