Execution
Follow the master commands
For the sponge cake preheat oven to 180 degrees Celsius and prepare either one or two 20cm/8 inch cake pan(s). Line bottom with parchment paper. Then divide the eggs into egg white and egg yolks. Use a bigger bowl for the egg yolks. If you have a glass or metal bowl, use that one for the egg whites. Be sure that bowl is free of fat/grease and that your mixer was properly cleaned. First beat the egg whites on medium speed with a pinch of salt until soft peaks form. Set aside. Without cleaning our mixer, beat the egg yolks with the sugar. Beat until the color becomes much paler and you have a creamy consistency. This usually takes several minutes.
Gently pour one third of the egg whites on top of the mixed egg yolks and sift the flour and cornstarch on top. Don't skip this step. It is important that the flour mix was sifted. Gently mix all ingredients with a spatula. Try to incorperate the flour mix and egg whites without losing volume. Add the last two thirds of beaten egg whites and gently fold the mixture. Don't overmix. Put batter into the prepared cake pans and immediately bake. Don't let the batter sit for too long as it will quickly lose volume. Bake for 35 minutes if using one springform or 25 minutes if using two. Let cool a little before gently getting them out of the form. Tip: if making the day before, wrap in cling wrap, it is much easier to cut in half once cold.
