1. In a heat-proof bowl set over a pan of simmering water, melt chocolate, stirring occasionally, until it smooth. Remove from heat; stir to cool slightly.

2. Working with one paper cup at a time, fill halfway with melted chocolate; invert cup over bowl of chocolate, and swivel to evenly coat sides. Gently but quickly reinvert cup; immediately place on a baking sheet in the refrigerator or freezer. If necessary, use a small pastry brush to fill in any holes so that no paper cup is visible. Let chocolate harden before filling, at least 30 minutes and up to 2 days; cover with plastic wrap once it is set.

3. In the bowl of an electric mixer fitted with the paddle attachment, beat cream cheese until it is smooth. Add peanut butter and sugar; beat until combined. In a separate bowl, whip cream to form stiff peaks; fold into peanut-butter mixture. Place in the refrigerator until it is slightly firm, about 5 minutes. Transfer to a pastry bag fitted with an Ateco #863 open-star tip, and pipe mixture into cups.

4. Place cups in a single layer in an airtight container or baking pan, and cover container or wrap pan with plastic, being careful not to touch tops of cups. Place in refrigerator until ready to serve, up to 4 hours. Sprinkle a few chopped peanuts over the top of each cup, and serve.