Chocolate Sponge Cake

Ingredients

4 room temperature eggs, separated
½ cup caster sugar
1 teaspoon bicarbonate soda
½ cup cornflour
1 tablespoon plain cake flour
3 tablespoons cocoa powder

Method

1. Preheat oven to 180°C.
2. Grease and line a 20cm springform tin.
3. Place egg whites in a large bowl and using an electric mixer beat the eggs on high speed until soft peaks form.
4. Sift together caster sugar and bicarbonate of soda into a separate bowl.
5. With the mixer still going, gradually add the caster sugar mixture one tablespoon at a time into the egg whites, beating until dissolved after each addition. When all the sugar is dissolved, turn off mixer.
6. Add egg yolks and beat again until combined.
7. In a separate bowl, sift dry ingredients three times to aerate and combine. Sift onto the egg mixture. Use a spatula to gently fold flours into eggs. This is the critical bit, use a ‘light’ hand and don’t over mix.
8. Pour the mixture into the prepared springform tin and bake for 20 minutes. The sponge is cooked when it has slightly come away from the sides and the top springs back when lightly touched.
9. Allow cake to cool in pan for 5 minutes before turning onto wire rack lined with baking paper to cool completely.
10. Use a large serrated knife to cut the cake horizontally into 2 even layers (insert toothpicks at intervals to use as a guide as you cut)

Notes & Tips for making sponge cake

The eggs should be at room temperature. 

Use really fresh eggs

Eggs and caster sugar must be whisked for a full 10 minutes with an electric whisk, until pale and thick. It’s thick enough when it’s about three times the volume. When you lift out the whisk, the thick mixture that drips off should leave a trail on top of the rest.

It’s crucial to fold in the flour with a sure but light touch – you don’t want to undo all that good whisking by knocking out the air!

To make the batter rise as much as possible, the bottom of the pan should have more heat than the top. So bake the cake on the bottom instead of middle shelf.