First Make the Witches Hats:

• Separate the Oreos and scrape out the cream, so that 12 Oreos will yield 24 witches hats.
• Fit a piping bag with a small piping tip, I used Wilton #14 and fill the piping bag with frosting two-thirds of the way full.
• Pipe a small dot of buttercream on the top of the Oreo and press a Hershey Kiss in the center.  Pipe more buttercream around the Hershey Kiss and add a few sprinkles.  Set the hats aside while you decorate the cupcakes.

Next decorate the cupcakes;

• Fit a piping bag with the large cupcake tip of your choice.  I used Ateco #828.
• Fill the piping bag with frosting two -thirds of the way full.  Pipe the frosting on each cupcake, swirling as high you want.
• Embellish the frosting with a few sprinkles.  

Put it all together:

• Gently place the witches hat to the top of the cupcake, pressing down slightly.