eggs, separated, at room temperature
cup + 2 Tablespoons (5.3 oz, 150 g) sugar
stick (125 g) butter, melted
cup (4 oz, 115 g) flour
cups (500 ml) milk, lukewarm
tsp vanilla extract
Mix egg whites until stiff. In another bowl, beat the egg yolks with the sugar, water and vanilla until light. Add melted butter and continue beating for another minute. Then add the flour and mix it in. Add the milk (it has to be lukewarm, otherwise the butter will harden) and beat until well incorporated. Gently fold in beaten egg whites using a spatula. Pour batter into a greased 8 inch x 8 inch (20 x 20 cm) baking dish (do not use spring form because batter is too liquid and the pan could leak) and bake in preheated 325 F oven for about 60 minutes or until the top is golden. Cool in the pan for at least 3 hours. Serve sprinkled with powdered sugar.