- 4 oz bittersweet chocolate, chopped (125 g)
- 1/2 cup unsalted butter, softened, cut into cubes (125 mL)
- 4 cups confectioner's (icing) sugar (1 L)
- 1 tsp rum extract (5 mL)
- In a heatproof bowl set over a saucepan of simmering water, melt chocolate, stirring until smooth. Let cool slightly.
- In work bowl of a food processor fitted with metal blade, process butter until smooth, about 30 seconds. Scrape down bowl. Add confectioner's sugar and process until it just begins to gather, about 15 seconds. With motor running, add chocolate and rum extract through the feed tube and process until smooth, about 30 seconds.