Light and Airy Génoise Sponge Cake
·Separate the eggs
Carefully separate the egg whites from the yolks. Getting the ratio right is key for this recipe, so it's best to weigh out your ingredients precisely beforehand.
Whip to stiff peaks
Put the egg whites into a clean bowl with the granulated and vanilla sugar. Whip on high speed until you get a really stiff, glossy meringue. It should hold sharp peaks that don't droop.
Gently fold in the yolks
Reduce the mixer speed to the lowest setting. Gradually add all the egg yolks to the meringue. Wait until they're fully incorporated and check that the mixture still holds a stable peak on the whisk.
Fold in the flour gently
Sift all the flour over the egg foam at once. Using the paddle attachment, mix on a slow speed, or fold it in very gently and carefully with a spatula using bottom-to-top strokes, to keep as much volume in the batter as possible.
Prepare the tin and preheat the oven
Preheat the oven to 150°C with the fan/convection setting. Line the base of the cake tin with baking paper. Pour the airy batter into the prepared tin and gently smooth the surface. Leave the sides ungreased and bare.
Fill the tin and bake
Bake in the preheated oven for 45–55 minutes. Do not open the oven door during the first 45 minutes, or the sponge will collapse. Once baked, remove it (test with a skewer or knife) and let it cool in the tin for 5–10 minutes.
Release and cool the sponge
Carefully run a thin spatula or knife around the edges of the sponge. Then turn the tin upside down onto a cooling rack and let the sponge cool completely – this will help flatten the top beautifully. Peel off the paper while the sponge is still slightly warm.
Store and rest
Once completely cool, wrap the sponge carefully in plastic wrap so it doesn't dry out. Let it rest at room temperature (or in the fridge), ideally until the next day. This makes it much easier to slice.
Trim and slice
The next day, unwrap the sponge. Using a long, ideally fine-serrated knife, first trim off the thin top crust so the surface is perfectly flat (if you want it flat rather than domed). Then slice the sponge horizontally into as many layers as you need.