Instant cake without flour or butter

Preheat the oven to 160 ºC (325 ºF). Grease 2 shallow 22 cm cake tins and dust with cornflour. Sift the cornflour, baking powder, cream of tartar and salt together. Beat the egg yolks lightly, add the sugar and beat until pale and fluffy. Sift the dry ingredients into the egg mixture and blend well. Whisk the egg whites until soft peaks form and fold into the cornflour mixture using a metal spoon. Divide the batter between the prepared cake tins, spreading the mixture evenly. Bake for 15-20 minutes until golden brown on top, a testing skewer comes out clean when inserted into the centre of the cakes and the cakes have shrunk from the sides of the tins. Turn the cakes out on to a wire rack and cool.
Divide each cake layer in two and spread with jam. Stack the layers on top of each other and dust the cake with a little icing sugar. Serve with stiffly whipped cream, if desired. Makes a medium-sized cake.