How to make
Preheat the oven to 320°F (160 °C). Grease a round baking dish measuring 8″ (20 cm) in diameter with a little butter. Melt the butter and let it cool. Heat the milk slightly as well and leave it. Beat the egg whites to snow and separately, beat the egg yolks with the sugar.
Add the melted butter and water to the yolks, beat until the products are fully mixed. Add the flour and mix again. Add the milk with vanilla in parts and whip the mixture until homogenized. Add the beaten to snow egg whites in three lots, while stirring them slowly with a spatula.
Put the mixture in the prepared form and bake for 45-60 minutes or until the cake is ready. If you see that it starts browning before 45 minutes have passed, cover it with paper on top and finish baking.
Allow the cake to cool completely, then cut it and sprinkle it with powdered sugar. Note that even after cooling completely, the cake will be softer at the base - this is because of the egg layer.
