I refer to this sponge in a lot of my recipes, it's the perfect base sponge for trifle, tiramisu, birthday cakes, swiss rolls, gateaux....It NEVER fails and is so light and fluffy, no one will suspect it's free from.
First things first...sieve both the flours together....4x! I've tried making this sponge with and without the sieving process and believe me it does make a difference.
Add the egg whites to a mixer and beat into firm peaks
Add the caster sugar a spoonful at a time and continue to beat until the whites become stiff and have a beautiful glossy sheen to them. You know it's ready if you take a pinch and rub your fingers together, if you can feel the sugar grains between your fingers you need to continue beating.
Add the egg yolks and mix quickly to combine
Fold in the sifted flours quickly but gently to prevent knocking too much air out of the mixture.
Add to your well oiled and lined tin(s)
Bake on 180°C for 20 minutes - keep a close eye to make sure the sponge does not catch, you know this will be ready when you get a perfect spongy bounce to the touch....the cooked smell is unmistakable!
depending on the recipe you plan to use this for allow to cool completely, or a little if planning on rolling.