- Unsalted butter, room temperature, for baking pan
- 1 pound semisweet chocolate, coarsely chopped
- 6 large eggs, room temperature
- 2 tablespoons sugar
- 1/2 teaspoon salt
- 2 tablespoons dark rum
- 1/2 cup heavy cream, whipped to soft peaks, plus more for serving (optional)
- Preheat oven to 350 degrees. Assemble a 9-inch springform pan with the raised side of the bottom part facing down; secure side. Butter pan; line side with a long strip of waxed or parchment paper. Butter paper. Wrap bottom and side of pan with aluminum foil (to prevent water from seeping in); do not tuck foil inside pan. Set a kettle of water to boil for step 5.
- In a large heatproof bowl set over (not in) a pan of simmering water, melt chocolate. Remove bowl from pan, and let cool to room temperature.
- In another large bowl, using an electric mixer on high, beat eggs, sugar, salt, and rum until mixture is thick, foamy, and forms a ribbon when you lift the beater, 4 to 6 minutes.
- Stir half the egg mixture into the cooled chocolate to lighten. Fold in remaining egg mixture, then whipped cream. Spoon batter into prepared pan, and smooth top.
- Place springform pan in a roasting pan; carefully pour hot water from the kettle to come halfway up the side of the springform pan. Bake until torte is set and firm to the touch, about 30 minutes.
- Transfer springform pan to a wire rack; remove foil and let cool to room temperature. Refrigerate torte in pan until well chilled, about 3 hours. To serve, release side. Using a knife dipped in warm water, cut torte into thin slices. Serve with whipped cream, if desired.
Baking this torte in a hot-water bath helps set the cake so it doesn't crack. Pick a top-notch variety of chocolate to achieve an intense cocoa flavor, and add rum for a delicious depth (or use your favorite liqueur).