I found a recipe in an old recipe book for this marble orange cake. It uses very few ingredients.
For the regular cake :
250 grams of butter, sugar and self-raising flour
I reduced the sugar to 200 grams.
Method : Cream sugar and butter till white and fluffy. Add in eggs, one by one. Add in flour.
Separate the batter into two portions.
PORTION A – ORANGE :
Add the zest and juice of one orange and mix.
PORTION B – CHOCOLATE
Add about 100 grams melted cooking chocolate or 2 tablespoons of cocoa powder.
In a suitable size baking tin, drop spoonsful of the chocolate and orange batter. Do not swirl as it will naturally form designs.
I said suitable size baking tin means the quantity of the batter must reach up to half the level of the tin. I use a 4″ x 6″ loaf tin.
Bake in a preheated oven for 45-60 minutes at 180 deg celcius. Leave the cake to cool.
Meanwhile, make an orange syrup with the zest and juice of 1 orange and 2 tablespoon icing sugar. Other sugar is fine but icing sugar will give a thicker syrup as there is cornflour in icing sugar.
Pour the orange syrup over the marble orange cake to get a zesty and yet chocolatey marble cake. Yummy.