How to Make It
Using scissors, cut the paper cups to a 1 1/2-inch height. Line a baking sheet with wax paper and set a wire rack on top. Working with 1 paper cup at a time and using a spoon, fill the cup with tempered chocolate, hold the cup upside down, tap gently and let the excess chocolate drip back into the bowl. Scrape the rim of the cup against the rim of the bowl to make a neat edge and place the cup upside down on the rack. Repeat to make 11 more chocolate cups. Let the cups stand for at least 5 minutes to firm up.
Using a sharp knife, scrape the cup rims to make clean, straight edges; this will also make the cups easier to unmold. Turn the cups right side up and refrigerate for 10 minutes. Carefully peel the paper off the chocolate cups. Set the cups right side up on a platter and store in a cool place.
In a medium stainless-steel bowl set over a pan of barely simmering water, melt the chopped chocolate, stirring occasionally. Remove the bowl from the pan, wipe the bottom dry and stir the chocolate until smooth. Let cool to warm room temperature. Add the peanut butter and stir with a wooden spoon until thoroughly blended.
Spoon the peanut butter and chocolate filling into a sturdy resealable plastic bag and press it to one side at the bottom of the bag. Snip off the tip of one corner. Pipe the peanut butter and chocolate filling into the chocolate cups until it almost reaches the rims. Tap the filled cups very lightly against the platter to release any air bubbles. Let the peanut butter cups stand in a cool, dry place for about 1 hour, or until set. The filling will be soft and creamy, but it will still hold its shape.
Tempering TipsTempering melted chocolate ensures that it will set up firmly with a glossy sheen. Any leftover chocolate can be tempered again later.
1. Chop 1 pound of room temperature chocolate into 1/2–inch pieces.
2. Put 2/3 of the chocolate in a glass bowl. Microwave at medium–high power for 30–second periods, stirring with a rubber spatula in the intervals, until 3/4 of the chocolate is melted, about 1 1/2 minutes.
3. Stir the chocolate until completely melted, then scrape it into a clean, dry, room temperature bowl. Measure the temperature of the chocolate with an instant–read thermometer; it should be between 100 and 115 degrees. Add the remaining chocolate in large handfuls, stirring constantly until the chocolate is at 88 degrees. If the chocolate becomes too cool, melt a few more tablespoons of chopped chocolate and stir them in to raise the temperature.
4. Dip the tip of a knife in the chocolate; the chocolate on the knife should begin to set within 1 minute. Use at once.
Cold sweetened whipped cream.