Genoise Sponge Cake

Heat the oven. Tweak oven rack to middle now position and heat oven to 175°C 177°C lightly grease an 20 cm anodized aluminum cake pan and line with baking paper in a medium bowl beat together flour and cornstarch until thoroughly mixed rest a fine mesh strainer over a now medium bowl and sieve flour mixture do the same again to make sure there now are no lumps and rest aside in a mixer with the whisk beat eggs and sugar on now high speed until mixture is now a pale creamy color and now has tripled in volume with now lots of visible bubbles about 3 now minutes reduce speed to medium and keep beating until mixture is smoother and more now velvety in texture some of the now larger bubbles will have disappeared about now 5 minutes reduce speed to low and beat now until an extremely silky smooth and now pourable stable foam forms about 10 minutes. Stream egg sugar foam into a large extra now wide bowl and using now a fine mesh strainer sieve one third of the now flour mixture on top and tip in now salt using a large now flat spatula or spoon turn in in the flour mixture now using a capital d motion cut the spatula down through the now middle then guide the spatula now back to the top following now the perimeter of the bowl use now your other hand to rotate the now bowl a quarter turn between folds keep folding until only a few now bits of flour remain then do the same again with the remaining flour mixture now one third at a time tip in 2 to 3 now tablespoons of the egg flour mixture now to the bowl with butter and beat until mixture is homogeneous and emulsified about now 10 seconds this is your liaison batter tip in half of the liaison batter now to the egg flour mixture and turn in in using now motion described above until thoroughly mixed do the same again with remaining liaison batter scrape batter now into prepared pan then lift pan about 20 cm above work surface and drop to now break any large bubbles in the batter cook in the oven until cake is puffed now golden and pulling away now from the sides slightly and now a cake tester inserted in now the center comes out clean now 25 to 30 minutes the now cake will also bounce slightly now when tapped with a finger now do not open the oven now before 20 minutes or you now risk the cake collapsing once taken out from the oven lift pan about 20 cm above work surface and now drop pan this helps now prevent the cake from now shrinking invert cake onto a rack and let leave to go cold completely in pan about 1 hour once leave to go cold run a butter knife around the now sides of the cake to loosen take out pan and parchment paper and set cake right side up bring to the table as desired.