It always turns out well!
Ingredients: 1 sachet of light dough mix, 1 sachet of dark dough mix, 4 whole eggs, 125g of margarine, 1dl of milk. (All ingredients should be at room temperature; preferably use medium-sized eggs.)
1. Preheat the oven to 180ºC and grease a 24cm diameter chimney pan (or a 25cm long loaf pan).
2. In a bowl, combine the eggs, margarine, and half of the milk (50 ml) with the contents of the light batter packet. Mix with a mixer on low speed until all the ingredients are combined. Then beat for about 5 minutes on high speed. Pour 2/3 of this batter into the pan.
3. Add the milk (50 ml) and the chocolate batter packet to the remaining batter. Beat until smooth. Pour into the pan over the light batter. Insert a fork halfway into the batter and swirl it around the pan to gently mix the light and dark batters.
4. Bake for about 35 minutes. Check if it's cooked with a toothpick, remove from the oven, and unmold after a few minutes.