- 1. Preheat the oven to 190C gas mark
- 2. Grease a non stick 30x40 cm baking tin.
- 3. Sift the flour cocoa powder and baking powder into a bowl add the salt and mix together well.
- 4. Beat the egg whites until stiff and then beat in the sugar. Add the vanilla essence and then mix in the marshmallows.
- 5. Pour the mixture into the prepared baking tin and bake for 15-17 mins. Allow to cool and then slice into 12 individual slices.