I made these last night for the Easter Baskets. Take a mini muffin tin and line it with the little paper liners. If you don't have the liners skip this step and I'll tell you how to deal with it later.
Put a few pieces of chocolate into each cup. I used a 70% cocoa extra bittersweet chocolate but you might want to use a semi sweet chocolate instead. You want to put enough chocolate in so that once melted it will fill the cup about 1/3 of the way.
Cover the mini muffin tin with a second mini muffin tin and place both on top of a pot of boiling water. I suppose a sheet of foil would work here as well. Keep peeking but don't let the condensation drip into the melting chocolate. Once melted add a dollop, you choose how much, of peanut butter. It should sink into the chocolate a bit.
Break several more pieces of chocolate and place on top of each peanut butter dollop. Recover the muffin tin and let top layer of chocolate melt. You may need to use a toothpick to make sure the chocolate spreads out and covers the peanut butter completely.
Remove the mini muffin tin from pot and place on rack to cool. It should be uncovered. If you've used the paper liners just let cool and you're done. If you didn't, wait for the chocolate to firm up a bit and then run a toothpick around the outer edge of each peanut butter cup. Transfer the tray to the freezer and, once frozen, use a butter knife to pop the peanut butter cups out. Make no mistake, its much easier to use the paper liners.
I've seen other ways to do this like in the microwave and they all taste good but this way maximizes the number of peanut butter cups you can make at one time while minimizing the number of dirty pots.
Now I'm back to room moving. The painting is complete. The rug is clean, except for some ink marks where our puppy chewed up a pen. To get the ink out spray a little hairspray on the spot and blot with a dry cloth. Its tedious and time consuming but it works.