Flourless Chocolate Torte

1. Heat oven to 300°F (150°C). Lightly grease a 9-inch (23cm) diameter springform pan with butter. Line bottom with a round of parchment paper. Place springform pan on a rimmed baking sheet.
2. In a double boiler over medium-low heat, melt chocolate, stirring until smooth. (Or melt chocolate in microwave in a large microwave-safe bowl on medium heat in 20-second increments, stirring after each interval, until smooth.) Remove from heat; whisk in butter, sugar, almonds and vanilla until smooth. Whisk in egg yolks.
3. In the bowl of a mixer fitted with the whisk attachment, whip egg whites with a pinch of salt until stiff peaks form.
4. Fold egg whites, one-third at a time, into chocolate mixture. Do not over-mix the batter, but make sure all egg white has disappeared.
5. Transfer mixture to prepared springform pan and smooth the top.
6. Bake for one hour, or until edge has set and middle has risen and cracked slightly.
7. Let cool completely in the pan (to room temperature). Then run knife around edge of cake and remove side of the springform pan.
8. You can decorate the top of the cake with a stencil and some icing sugar. If desired, top with sweetened whipped cream after slicing.

Note: For neat presentation, use a wet knife to slice the cake, wiping the blade between cuts.