Preheat oven to 325 F degrees. Grease a 8 inch x 8 inch baking dish.

Separate eggs and add the egg whites to a mixer and mix until egg 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 extract and continue beating for another minute

Add the flour and mix it in until fully incorporated.

Slowly add 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 about 70 minutes or until the top is lightly golden. The baking time could vary depending on the oven, so take a look at around 40 minutes and see how it looks.

Sprinkle some powdered sugar after cake has cooled and cut into squares.

Enjoy.