Vó Dora's chocolate cake

Arguably, the best cake in the world. Just ask any of Vó Dora's daughters, grandchildren and great-grandchildren. The only problem is that my late Hungarian grandmother never wrote down a recipe. She was a fantastic cook, but was never able to explain how she achieved such mouth-watering results. When asked about this recipe, she would say "Oh, just a little flour, some eggs, sugar and butter". Fortunately, one of her daughters decided to watch her making this cake with pen and paper at hand, and took notes of everything Vó Dora did. She was then able to pass on the recipe to her sisters and whoever else wanted to know the secret of this absolutely delicious cake. Here at home, it has become our traditional birthday cake. The one in the picture is for Júlia's 15th birthday. Happy birthday, Júlia.

Ingredients

• 350 grams unsalted butter at room temperature
  
• 2 cups sugar
• 2 cups flour
• 6 eggs at room temperature
  
• 1/2 cup milk at room temperature
• 3 teaspoons baking powder
• 3 or 4 tablespoons sugar-free powdered cocoa
• 3 or 4 tablespoons vanilla-flavoured sugar
• a drop of rum
• 4 tablespoons apricot or strawberry jam

1. You'll need two large mixing bowls and one small one; separate the egg yolks from the whites, placing all 6 whites together in a large bowl, 4 of the yolks in the other large bowl and the remaining 2 yolks in the small bowl.
2. Whip the whites till fluffy, adding 1 cup of sugar little by little during the process.
3. To the bowl with the 4 yolks, add 200 grams butter, 1 cup sugar, 2 cups flour and mix well.
4. When the above is homogenous, mix in the milk and then, last of all, the baking powder.
5. Pour the whipped egg whites onto the above and mix everything very gently with a wooden spoon, always in the same direction.
6. Place the cake dough in a well-greased baking tin and bake for around one hour in a medium-hot (170 degrees Celsius) oven (for baking, electric ovens far better than gas ovens).
7. To test if the cake is cooked, when you think it's done, stick a toothpick into its centre and see if it comes out completely dry - only then will it be fully cooked.
8. Let the cake cool to room temperature and slice it in half (horizontally) for the filling.
   
9. To the small bowl with 2 yolks, add the vanilla-flavoured sugar, the powdered chocolate, 150 grams butter and a drop of rum, then mix well with a fork.
10. Spread a little of the above chocolate spread onto one half of the cake, then spread some jam on top and put the two halves back together, as in a sandwich.
11. Cover the whole cake with the remaining chocolate spread.