Light Marble Cake

📝 Ingredients

• 3 eggs + 120 g caster sugar
• 1 tsp vanilla extract
• 2 pots plain yoghurt (125 g each)
• 40 g unsalted butter
• 220 g plain flour
• 1 sachet baking powder (11 g)
• 20 g unsweetened cocoa powder + 3 tbsp semi-skimmed milk
• 1 pinch of salt

🍴 Utensils

• 26 cm loaf tin
• 2 mixing bowls
• Whisk
• Spatula
• Knife
• Wire rack

📖 Steps

1. Preheat the oven to 170 °C. Line the loaf tin with baking paper, leaving it overhanging on the long sides so the cake is easy to lift out. Melt the butter in the microwave for 30 seconds and leave to cool slightly.
2. In a bowl, whisk the eggs with the sugar, vanilla extract and pinch of salt for 2 to 3 minutes, until the mixture turns pale and clearly increases in volume: this is what makes the cake soft despite the small amount of butter.
3. Add the yoghurts, then the warm melted butter, and whisk together. Fold in the flour and baking powder in two goes with a spatula, just until there are no more lumps or streaks of flour. Don't overwork the batter.
4. Pour half the batter into the second bowl, about 400 g: weighing it is easiest. Add the cocoa and milk, then mix until the batter is evenly brown and as soft as the plain batter.
5. Spoon a large dollop of plain batter into the tin, then one of cocoa batter on top, and so on, alternating until both batters are used up. Don't mix at this stage: the layers must stay distinct.
6. Plunge a knife blade right to the bottom of the tin and draw 3 or 4 large zigzags along the whole length, without overdoing it: if the two batters are mixed too much, you'll get a uniformly beige cake instead of beautiful marbling.
7. Bake for 40 to 45 minutes in the middle of the oven, until the cake is well risen and golden and a knife inserted in the centre comes out clean. If it browns too quickly, cover it with a sheet of foil halfway through.
8. Leave to cool for 10 minutes in the tin, then lift out onto the wire rack using the baking paper and leave to cool completely before cutting into 8 slices: while still warm, the cake crumbles.