This is a simple, classic sponge. For best results, sift the dry ingredients well.
50g butter, softened
4 eggs at room temperature
¾ cup caster sugar
¾ cup cornflour
2 tsp self-raising flour
1½ tsp baking powder
1 cup thickened cream, whipped to soft peaks
¼ cup fresh passionfruit pulp
2 cups pure icing sugar
Preheat oven to 200C. Grease two 20cm round sponge tins with softened butter. Line the bases and sides with baking paper, making sure the paper is 8cm high all the way around.
Separate eggs. Beat whites with an electric mixer, using the whisk attachment, until stiff peaks form. Add sugar gradually, beating on medium speed. Add egg yolks, one at a time, beating on low speed.
Sift cornflour, self-raising flour and baking powder into a bowl. Sift again. Fold into egg mixture in two batches, using a spatula. Do not overmix.
Divide mixture between the sponge tins. Bake in oven for 20 minutes until well risen and light golden. Do not open the door during the baking time. To test, press sponge lightly with a finger; it should spring back.
Remove from oven and cool on cake rack for a few minutes. Gently turn out of tins, peel away the baking paper and cool completely. When cool, fill with cream.
Make icing by mixing passionfruit pulp with icing sugar. Ice cake with a hot, clean knife.