Adapted from Martha Stewart
6 tablespoons unsalted butter, cut into pieces
3 ounces semisweet chocolate, finely chopped
¼ cup packed light-brown sugar
1 teaspoon pure vanilla extract
¼ teaspoon salt
¼ cup all-purpose flour
2 tablespoons cocoa powder
1/4 cup dark rum
Coarse sanding or turbinado sugar, for rolling
Preheat oven to 350. Coat a small baking sheet (8x8 or 9x9) with cooking spray; set aside. Melt butter and chocolate in a small heatproof bowl set over a pan of simmering water, stirring occasionally until chocolate is melted or microwave butter and chocolate in heatproof bowl until chocolate is melted, stirring at 15 second intervals.
Whisk together eggs, brown sugar, and vanilla. Add to chocolate mixture, then stir in flour and cocoa powder. Spread evenly into baking sheet and bake until a toothpick inserted in the center comes out mostly clean but with some crumbs attached, 10-12 minutes. Let cool for a few minutes, but you don’t have to cool completely.
Break up brownie into small pieces; transfer to the bowl of an electric mixer fitted with the paddle attachment or use a hand mixer. Slowly pour in rum and beat until crumbs start to adhere with rum to form a ball.
Shape into 1-inch balls (mine are 1 ½”), and roll in sanding sugar to coat. Transfer to a baking sheet; refrigerate, uncovered, until cold, about 2 hours. Serve chilled or at room temperature. Makes 18-24.