Pâte génoise

03 — Method

1. Preheat the oven to 180 °C (350 °F) fan. Butter and flour a 22 cm (9 in) cake pan and tap out the excess.
2. In a bowl over a water bath (simmering, never boiling), whisk the whole eggs with the sugar for 5 minutes, until barely warm.
3. Remove from the water bath and beat with an electric mixer for 8 to 10 minutes, until tripled in volume and falling in a thick, slow ribbon.
4. Sift the flour over in 3 additions and fold in gently with a spatula, lifting from the bottom, never stirring in circles, so you don't break the air bubbles.
5. Mix a small ladle of batter with the warm melted butter, then fold this very gently into the rest of the batter.
6. Pour into the pan right away (the batter deflates quickly), smooth the top and bake immediately.
7. Bake for 25 to 30 minutes at 180 °C (350 °F) without opening the oven for the first 20: it's done when golden and risen and a knife inserted in the center comes out clean.
8. Unmold while warm by gently inverting onto a rack and let cool completely before cutting or filling.
9. For a chocolate genoise, replace 20 g of the flour with 20 g unsweetened cocoa (105 g / ¾ cup + 2 tbsp flour and 20 g / ¼ cup cocoa sifted together) — ideal for a Black Forest cake or a triple-chocolate Bavarian cream.