Beat 3 eggs and separate the egg yolks from the egg whites. Use an empty plastic bottle to suck up the egg yolk and press it out into another container.
Add the 1/3 cup of sugar to the egg yolks and beat the ingredients into a thick, creamy mixture. Add the melted butter and mix well. Next, add the flour and mix it up. Add the vanilla essence and milk in one go and mix together.
Add 1 tbsp. of sugar to the egg whites and whisk them. Mix the egg whites with the remaining ingredients and pour the mixture into a loaf pan.
Distribute a handful of berries into the batter and bake it at 280°F for 50 minutes. It is important to bake the cake for a long time and to mix the ingredients separately, because this helps the cake become nice and fluffy.