Place 12 cupcake liners in a standard size cupcake pan.
Melt a little over half of the chocolate in a microwave-safe dish at 30-second intervals stirring in between until mostly melted, then stir to melt all the way. You can also use a double broiler to melt the chocolate.
Using a spoon or cookie scoop, put an equal amount (about 1½ teaspoons) of melted chocolate in each cupcake liner, barely filling the cup. To evenly disperse the chocolate, drop the pan on the counter a few times. Place pan in the freezer for 10 minutes to harden.
Whisk together the peanut butter, butter, and powdered sugar with a hand mixer until smooth, about 1-2 minutes. Place an equal amount of peanut butter mixture in each cup. Drop the pan on the counter a few times to evenly disperse the peanut butter layer over the chocolate. Place in the freezer for 10 minutes to harden.
Melt the remaining chocolate and spoon about a teaspoon on top of the peanut butter mixture. Again, drop the pan on the counter to evenly disperse the chocolate. Place peanut butter cups back in the freezer for about 10 minutes to set.
Remove cupcake liner from the peanut butter cup and enjoy it.