- Preheat the oven to 300 °F (150 °C). Grease a 9-inch (23 cm) springform pan, line the bottom with parchment, then grease and dust the entire pan with sugar, tapping out any excess.
- Melt the chocolate and butter in a metal or glass bowl placed over a pot of barely simmering water, stirring constantly. Once melted, remove the bowl from the heat and let cool slightly.
- Whip the egg whites with 2 Tbsp (25 g) sugar until the whites hold a soft peak (when the whites curl when the beaters are lifted). Set aside.
- In another bowl, whip the egg yolks with the remaining ¼ cup (50 g) of sugar and the vanilla until doubled in volume, about 4 minutes. Fold the melted chocolate mixture into the whipped yolks, and then fold the whites into the mixture in 2 additions. Spread the batter into the prepared pan.
- Bake the torte for 35 minutes. As soon as you remove the cake from the oven it will begin to fall, but it is supposed to. Cool the cake to room temperature then chill for at least 2 hours before slicing and serving. The cake should be stored refrigerated and sliced while cold, but if you can, allow the cake slices to sit out at room temperature for 10 to 20 minutes before serving to really let that melt-inyour- mouth warmth build.