- Preheat oven to 200°C (400°F).
- Grease and sprinkle six 125-mL (½-cup) ramekins with sugar. Set aside.
- Cook the raspberries and sugar in a saucepan over medium heat and simmer for 5 minutes. Set aside.
- Sift the flour and cocoa powder together in a small bowl. Set aside.
- Heat the milk, butter, 45 mL (3 tbsp.) sugar, and vanilla extract in another saucepan over medium heat until mixture just starts to boil.
- Remove from heat, add the chocolate, let sit 1 minute and then stir until completely melted and well blended.
- Add the flour mixture to the chocolate mixture. Whisk the mixture until well blended. Add egg yolks one at a time, mixing well after each addition. Set aside.
- Use a hand-held mixer to beat egg whites in a large bowl until soft peaks form. Gradually add remaining sugar and continue beating until stiff peaks form.
- Use a spatula to incorporate the reserved raspberry purée into the chocolate mixture. Gently fold the beaten egg whites into the batter.
- Spoon the chocolate mixture into the ramekins, filling them 1 cm (1/2 inch) from the top. Place ramekins on a baking sheet. Bake 15 minutes or until soufflés rise and the centre is lightly set. Sprinkle with icing sugar. Serve immediately.
Replace the frozen raspberries with mixed berries, blueberries, or cranberries.