Steps
1. Preheat the oven to 350°F.
2. Grease 1 ramekin with some butter.
3. In a bowl, stir together melted butter, sugar, cocoa powder, flour and baking powder.
4. Add the Grand Marnier and whisk until the mixture is homogeneous.
5. In a different bowl, beat the egg whites until soft peaks form. Add 4 teaspoons of sugar while stirring and beat until stiff peaks form.
6. Gently fold in the egg whites, in three batches, in the chocolate mixture.
7. Pour the mixture in the greased ramekin and bake for 12 minutes.
8. Once baked, sprinkle the top with some extra sugar, and serve.