Preheat oven to 325°. Grease a 8x8 baking dish.

Separate eggs and add the whites to a mixer and mix until whites are stiff. Place egg whites in a bowl and set aside.

Beat the egg yolks with the sugar until light. Add butter and vanilla and continue beating for another minute or two after which you can add the flour and mix it in until fully incorporated.

Slowly start adding the milk and beat until everything is well mixed together. Add the egg whites a third at a time and gently fold them in using a spatula, repeat until all egg whites are folded in

Pour batter into baking dish and bake for 40 to 70 minutes or until the top is lightly golden. The baking time could vary greatly depending on the oven, so take a peek at around 40 minutes and see how it looks.

Sprinkle some powdered sugar after cake has cooled.