Preheat the oven to 180C. Sieve the dry ingredients , flour, cornstarch, salt and baking powder. Line your loaf tin with paper or butter and flour.
Using a stand or handheld mixer, cream the butter with the sugar for 3 minutes, until fluffy. Then add the eggs one by one and continue mixing until you no longer see them. Add the vanilla too. Then add the yogurt and mix.
Add in the dry ingredients and mix preferably by hand or very little with the mixer. If you overmix you will end up with a very dense cake.
Take half of the cake mixture and add the cocoa powder to it. Sieve the cocoa into the batter bowl to get rid of any lumps. Then mix by hand until incorporated.
Using 2 spoons for each flavor, pour some of each into the loaf pan making sure the vanilla and chocolate are distributed. Then take a skewer and mix them slightly making swirls that look really beautiful.
Bake for 35-45 minutes at 180C, mine took exactly 40 minutes. Enjoy with some Squeezy!
