Austrian Marbled Cake

Directions

1. 1
   Preheat oven to 160 degrees Celsius.
2. 2
   Mix in a bowl 300 gr. flour and baking powder, set aside.
3. 3
   Separate the eggs.
4. 4
   IN a medium bowl, whisk egg yolks, confectioner's sugar, salt, vanilla, sugar and lemon zest until frothy (at least 10 minutes).
5. 5
   In a large bowl combine milk and the remaining flour and whisk until smooth, then add the yolk mixture.
6. 6
   Pour the oil in a steady stream while stirring constantly.
7. 7
   Gradually add the remaining flour to the egg mixture.
8. 8
   With an electric mixer, beat the egg whites. When they are foamy, gradually add the sugar and continue beating until stiff peaks form.
9. 9
   Gently fold the egg whites into the batter with a rubber spatula.
10. 10
    In another bowl, mix the cocoa and the rum and add one third of the cake batter, mix gently.
11. 11
    Grease a cake pan or bundt cake pan.
12. 12
    Pour half the vanilla batter. With a spoon, top with the chocolate batter, and finish with the remaining vanilla batter.
13. 13
    Bake for about 1 hour until a knife inserted on the center of cake comes out dry.
14. 14
    Let cool for about 10 minutes before unmolding it and then let it cool completely on a wire rack.
15. 15
    Sprinkle with confectioner's sugar before serving.