Marble Cake

Directions

1. 1
   Preheat the oven to 180C.
2. 2
   Beat the butter with 200 grams of sugar and the vanilla extract until light and foamy.
3. 3
   Add the egg yolks, one at a time, then add 2 tablespoons of flour, the milk, and grated lemon peel.
4. 4
   Beat the egg whites to stiff peaks, add the remaining 50 grams of sugar, and continue beating until the peaks are firm.
5. 5
   Sift the remaining flour with the baking powder.
6. 6
   Carefully fold the egg whites and the flour into the butter mixture.
7. 7
   Divide the batter into 2 bowls, add the cocoa, chocolate, and rum to one of the bowls.
8. 8
   Pour half of the plain batter into a buttered and floured cake pan, then add the chocolate batter and add the remaining plain batter on top.
9. 9
   Use a fork to make spirals in the batter for the marble effect.
10. 10
    Bake for 50 to 60 minutes or until a toothpick inserted in the center comes out clean.
11. 11
    Remove the cake from the oven, let it cool completely and sprinkle it with powdered sugar before serving.