1

Preheat the oven to Gas Mark 4/180ºC/fan oven 160ºC. Line a 20cm (8 inch) square baking with non-stick baking parchment.

2

Place the sugar and low fat soft cheese in a large bowl and whisk together until pale and soft. Add the egg yolks and whisk until well combined. Whisk in the vanilla extract.

3

In a clean, grease-free bowl whisk the egg whites until they hold stiff peaks.

4

Sift the flour, bicarbonate of soda and cocoa into the soft cheese mixture with the milk. Stir well until combined. Carefully add the egg whites folding in slowly to retain the air. Spoon into the tin.

5

Mix together the rice crispies, icing sugar and melted margarine and scatter over the surface. Bake for 25 mins until risen and spongy to feel. Cool in the tin, before turning out and cutting into pieces. Once cold store in airtight container. Best eaten the same day otherwise the topping goes soft.