Place chocolate in a bowl and microwave for 30 seconds, then stir. Continue microwaving in 15-second increments, then stirring, until the chocolate is melted and smooth.
In a separate bowl, warm up peanut butter in the microwave for 30 seconds. Then stir in the powdered sugar until smooth. It shouldn’t be very sticky anymore and you should be able to press it between your fingers and it holds together.
Using a teaspoon (the one from the silverware drawer), scoop up a bit of the melted chocolate and drip it into the cupcake liners. Using the tip of the spoon, gently nudge it to the edge of the liner, so the entire bottom is covered in a thin layer of chocolate.
Next, scoop up a small bit of the peanut butter mixture and roll it into a 1″ ball. Press the ball flat between the palms of your hands to form a disc.
Place this disc of peanut butter on top of the chocolate layer in the cupcake pan.
Finally, using a teaspoon again, scoop up some more of the melted chocolate and drizzle it over top of the peanut butter in a thin layer. Again, using the tip of the spoon, gently nudge it around so that it drips down all sides of the peanut butter.
Place in the refrigerator for 1 hour to chill.
Then just remove the cupcake liners and enjoy!