Sponge cake recipe

Ingredients . 4 eggs . 100 castor sugar . 100 flour(ou 80 g flour and 40 g cacao)
1. Sieve the flour and the cocoa in order to mix these ingredients and to remove the lumps. If you make a sponge cake without cocoa, compensate in flour for the weight of cocoa.
2. Put eggs and sugar in a pan
3. Heat the pan on very soft fire, and whisk the mixture with an electric whip. The heat makes possible to obtain a temperature between 40 and 50°C , but not more, in the pan. This temperature helps an adequate development; higher temperatures would burn the eggs and attach to the bottom.
4. When the preparation is well assembled and homogeneous, stop fire, and continue whisking to cool it a little. Stop whipping when the blades leave a quite visible trace in the paste.
5. Add the flour in several times using the sieve, this avoids depositing too much flour at the same time.
6. With a spatula or wooden spoon incorporate the flour to the preparation and performing vertical gestures at the same time. This makes possible to coat the flour without letting falling down the eggs.
7. You must proceed quickly, because the sponge cake does not support waiting for long before cooking.
8. Pour the sponge cake in a plate oven proof whose form depends on your needs (round, flat, all is possible), and bake at 160°C for approximately 20 minutes.
9. Turn out as soon as it is removed from the oven and let it cool on a grid. The sponge cake can be kept for 2 to 3 days.