Line baking sheet with parchment paper.
Scrape melted chocolate into 1 quart zipper lock plastic bag, press out air, and seal tightly.
Cut small hole in 1 corner of bag.
Pipe quarter sized circles of chocolate onto lined baking sheet.
Sprinkle chocolate circles heavily with nonpareils.
Let stand until hardened, about 30 minutes.
Transfer to airtight container and store at room temperature for up to 1 week.