Some years later, (and many failed sponges later) I came across the recipe card and thought I'd give it a try. Much to my utter amazement, I made my first successful sponge cake!
I've made it many, many times since and have even left out the raising agents and it still worked, though wasn't quite as light.
Recently in Nyabing, the local CWA held a cooking morning where we demonstrated how to make Cream Puffs and my No Fail Sponge Cake.
Here's a photo of a couple of successful students with their sponge:
Unfortunately, the commercial oven wasn't ideal and they didn't rise quite as much as they should have, but they were still good sponge cakes!
No Fail Sponge Cake
4 large eggs, room temperature (stale eggs are best)
1/2 cup caster sugar
1/2 cup cornflour
1/2 cup custard powder
1 tsp plain flour
1/2 tsp bi-carb soda
1 tsp cream of tartar
Preheat oven to 180C fan forced
Grease and line the bases of 2 high sided 20cm cake tins with baking paper and flour the sides.
Using whisk attachment of mixer, beat eggs for 8 minutes. Beat for an extra 2 minutes if you have beater blades.
Meanwhile, sift flour, custard powder and raising agents three times.
Add sugar and beat for a further 3 minutes.
Use whisk from mixer (or beater blade) to incorporate dry ingredients.
Pour into tins and tap gently to remove large air bubbles.
Bake for 18 - 20 minutes.
Use raw caster and add 2 tsp ground ginger and 1/2 tsp cinnamon
Replace 1/4 cup cornflour with 1/4 cup dark cocoa powder. Increase sugar amount to 2/3 cup.