I made yesterday a marble cake. You can substitute butter milk with milk, I used 3/4 cup sugar and you can mix a bit with stevia or birch sugar. I used the organic cacao powder I got at Walmart.
I used also r a p eseed oil (sunflower oil works too) instead of butter. There are many various recipes online but this one is the closest I made and is about the Swiss recipe I learnt at school. I did use the loaf baking pan but the round one is okay as well. - I left it too long in the oven cos I forgot to set the timer… it turned out a tiny bit dry, so watch out!
