Orange Flavoured Sponge Cake

1) Pre-heat your oven at 170 degrees Centigrade (gas mark 6)
2) Rub the sugar lumps against the orange, to allow the essential oil to impregnate the sugar
3) Then crush them, and add the caster sugar and vanilla sugar
4) Place the sugar, the salt and the egg yolks in a large salad bowl and whisk until light and fluffy, then add the "Grand Marnier" (optional).
5) Mix the wheat flour and 50g of the corn flour/starch together then add the egg yolk mixture, mix well.
6) Whisk the egg whites until strong and fluffy foam, bind into the egg yolk and flour mixture, delicately bringing the mixture a the bottom of the bowl on the top of the egg white.
7) Line the bottom of the tin mould (non-stick preferably) with the 30g of corn flour and the caster sugar left over mixed together.
8) Pour the mixture in your tin, bake for 50 minutes (check the cooking with tip of an office knife. It should come out hot and dry)

You can serve the orange sponge cake sliced, with some ice-cream, custard or a creamy hot chocolate (with marshmallow!), well use you imagination to find an excuse to spoil yourself with a nice slice of cake.
This family recipe has a special characteristic: housewives and Grand Ma' Margot were use to replace part of the flour in their cake recipes with some corn flour to give them a lighter texture. Personally I advise the use of corn flour in cakes!