Gateau de Savoie (French Sponge Cake)

This is very simple and quick cake to make and that fresh lemon taste, definitely my favorite flavor!

The story of the Gateau de Savoie (from L'Histoire du Gâteau de Savoie .) This cake was invented in 1358 in Savoy a region in South-East of France, hence its name. The Count of Savoy was receiving at his table his emperor Charles IV of Luxembourg (Savoy was not French at that time). The Count asked his pastry chef, Pierre, to make a cake as light as a feather, likely to appeal to the emperor. Pierre had the idea of ​​beating egg yolks and sugar long enough until they became very pale yellow, and lightening the preparation further by adding the egg whites and flour. Since there was no thermostat yet, he baked the cake in wooden plate to allow for softer cooking, giving the dough time to develop his proverbial lightness.
Note that this cake doesn't contain any fat apart from half a teaspoon to butter the pan.

Ingredients
6 eggs
1-1/4 cup granulated sugar
1 cup all purpose flour
1/3 cup corn starch
3 tablespoons luke warm water
Zest of one lemon (preferably organic)
9 inch savarin mold (or a regular pan)
Butter for the pan
2 tablespoons icing sugar for decoration

Directions

1. Preheat oven to 375 degrees F 
2. Separate the egg whites and yolks 
3. In a large bowl beat the egg yolks and sugar with an electric mixer to obtain a pale yellow colour. 
4. Add the water and lemon zest and mix few more seconds. 
5. Gradually add the flour and starch while still beating. 
6. Whisk the egg whites until very firm and fold in delicately in the flour mixture, a small quantity at a time. 
7. Butter the mold and pour in the batter. 
8. Bake at 375 degrees F (200 degrees C) for 5 minutes, then turn down the oven to 350F and continue cooking for another 40 minutes. 
9. Poke the middle of the cake with a skewer or a toothpick to check if it’s done. If it comes out clean, the cake is ready. 
10. Run a thin spatula or knife around the edge of cake to loosen the cake sides from pan and shake to unmold. Invert the cake onto a cooling rack. 
11. When it’s cooled, transfer to a plate then dust the surface with sifted icing sugar.