Place the chopped bittersweet chocolate in a microwave-safe bowl. Microwave in 30-second bursts, stirring after each, until the chocolate is smooth and glossy.
In a separate bowl, mix the creamy peanut butter, softened butter, and sifted powdered sugar until smooth and well combined. The mixture should be thick but scoopable.
Pour the melted chocolate into the peanut butter mixture and stir thoroughly until fully integrated, creating a thick, uniform dough.
Using a small scoop or teaspoon, portion out the mixture and roll into 1-inch balls with your hands, placing each on a parchment-lined baking sheet. The mixture will be firm but pliable.
Chill the shaped truffles in the refrigerator for at least 30 minutes until firm and set.
Meanwhile, melt the additional chocolate in the microwave in short bursts, stirring until smooth and slightly cooled.
Remove the chilled truffles from the fridge. Dip each into the melted chocolate using a fork or dipping tool, letting excess drip off before placing back on the parchment.
Optional: Roll the coated truffles in crushed pretzels, chopped nuts, or dust with cocoa powder for extra flavor and texture.
Let the coated truffles sit at room temperature for about 10 minutes to set the chocolate, or refrigerate for quicker results.
Once the chocolate is firm and glossy, transfer the truffles to a serving dish or store in an airtight container in the fridge. Enjoy these rich, nostalgic bites!
