Preparation
Preheat the oven to 180°C (160°C fan, gas 4). Grease a ring cake tin with butter and sprinkle with crumbs.
![](https://blog.liebherr.com/wp-content/lh-recipe-images/000121/000121_step_1_M.jpg)
Whisk the butter until soft and creamy.
![](https://blog.liebherr.com/wp-content/lh-recipe-images/000121/000121_step_2_M.jpg)
Whisk in the sugar until creamy.
![](https://blog.liebherr.com/wp-content/lh-recipe-images/000121/000121_step_3_M.jpg)
Add the vanilla sugar and salt.
![](https://blog.liebherr.com/wp-content/lh-recipe-images/000121/000121_step_4_M.jpg)
Grate the zest from the lemon and beat into the batter.
![](https://blog.liebherr.com/wp-content/lh-recipe-images/000121/000121_step_5_M.jpg)
Gradually add the eggs, whisking constantly.
![](https://blog.liebherr.com/wp-content/lh-recipe-images/000121/000121_step_6_M.jpg)
Add some milk.
![](https://blog.liebherr.com/wp-content/lh-recipe-images/000121/000121_step_7_M.jpg)
Sieve the flour with the baking powder and starch and add to the batter, alternating with the milk until a soft dropping consistency is formed.
![](https://blog.liebherr.com/wp-content/lh-recipe-images/000121/000121_step_8_M.jpg)
Spoon half the mixture into the prepared tin.
![](https://blog.liebherr.com/wp-content/lh-recipe-images/000121/000121_step_9_M.jpg)
Mix the cocoa powder into the other half. Add a little milk if necessary.
![](https://blog.liebherr.com/wp-content/lh-recipe-images/000121/000121_step_10_M.jpg)
Spread the chocolate mix evenly over the plain mix and pull a fork randomly to swirl the mixtures together.
![](https://blog.liebherr.com/wp-content/lh-recipe-images/000121/000121_step_11_M.jpg)
Bake in the preheated oven for about 1 hour. Test with a skewer. Remove from the oven, allow to cool slightly, turn out of the tin and cool completely. Sprinkle with icing sugar and serve in slices.
![](https://blog.liebherr.com/wp-content/lh-recipe-images/000121/000121_step_12_M.jpg)