8ouncessemisweet or bittersweet chocolate, coarsely chopped
1 1/2cupsall-purpose flour
1cupconfectioners sugar, sifted
In a heatproof bowl set over a pot of simmering water, melt the chocolate and butter until smooth. Remove from heat and let cool to room temperature.
In the bowl of an electric mixer fitted with a paddle attachment, beat the eggs and sugar until thick, pale and fluffy (about 5 to 6 minutes). Add the vanilla and mix to blend. Add the cooled chocolate mixture and beat until incorporated.
In a medium bowl, whisk together the flour, salt and baking powder. Add dry ingredients to the chocolate mixture, stirring just until incorporated. Cover with plastic wrap and refrigerate until firm enough to shape into balls (several hours or even overnight).
Preheat oven to 325 degrees F. Line two baking sheets with parchment paper.
Place the confectioners sugar in a shallow bowl. Form the chilled dough into 1 inch balls, then roll each ball in the sugar to coat. Coat balls completely, so that no chocolate is showing through. Place the sugar-covered balls on the prepared baking sheet, about 2 inches apart and bake for 8 to 10 minutes, or just until the edges are slightly firm but the centers are still soft. Remove from oven and place on a wire rack to cool.