Preparation:

1. In a small bowl using an electric mixer, mix together the peanut butter, powdered sugar and salt, until well blended and firm.
2. Break the chocolate bars into pieces.  Slowly melt in a double boiler set over hot, not boiling water. 
3. Lightly oil the cups of a muffin tin.  Spoon some chocolate (about 1 1/2 teaspoons) into the bottom of the tin, then using a spoon, draw some chocolate up the sides, so there is a slight center indentation.  Place the tray in the refrigerator to set.
4. Take a teaspoon of peanut butter and place in the center, using your fingers, press it out to form a disk (do not go all the way to the edge of the chocolate).
5. Reheat the chocolate, then spoon over the top to cover completely, allowing the chocolate to run around the outside edge of the cup to fully enclose the peanut butter filling.  Place in refrigerator to firm.
6. When ready to unmold, run a knife carefully around the edge of the cup and gently remove.   Makes about 12 cups.
*Cook's Note - The amount of peanut butter you need depends on how much filling you want in each cup.  Just keep the proportions the same 1/2 sugar to 1 peanut butter.
These can also be made in a mini-muffin pan.