Preheat the oven to 180c.
Grease a cake tin with some butter.
In a mixing bowl,combine the flour,baking powder and baking soda.
Add the cocoa powder and sugar and mix well with a spatula.
Now add the wet ingredients (oil,yogurt and milk) one by one.
Combine everything well together.
Take a marmalade in a microsafe bowl. Heat for 10-20 seconds just to loosen it up.
Add it to the batter and mix well.
Pour the batter in the prepared cake tin.
Bake for 30-35 minutes at 180c.
Check if it is done by inserting a knife in the center.
Cool for 10 minutes and slice them into squares.