Preheat your oven to 180°C (350°F). Melt 200g dark chocolate (70% cocoa minimum) in a bain-marie or microwave. Separate 4 eggs. Mix the yolks with 100g sugar-free applesauce and the melted chocolate. Add 50g wheat flour and 1/2 sachet baking powder. Whisk the egg whites until stiff peaks form. Gently fold the egg whites into the mixture. Pour the batter into a cake pan. Bake for 25 minutes. Total time: 40m