- 4 eggs
- 200 g sugar
- 200 ml milk
- 200 ml vegetable oil
- 300 g flour
- 10 g baking powder
- 1 sachet vanilla sugar
- grated lemon zest
- 2 tbsp cocoa powder
- 1 pinch of salt
Preheat the oven to 180°C (360°F) and prepare your loaf pan by greasing it thoroughly, then dusting it lightly with flour or lining with baking paper.
Separate the eggs carefully, placing whites into a clean bowl. Add a pinch of salt and whisk vigorously until stiff peaks form, keeping the mixture airy and stable.
Gradually incorporate the sugar into the whipped egg whites, whisking continuously. Maintain steady movements to achieve a glossy, firm meringue that holds its shape beautifully.
Beat the egg yolks with milk and vegetable oil in another bowl. Add vanilla sugar and lemon zest, mixing until smooth, fragrant, and evenly combined throughout.
Fold the yolk mixture gently into the meringue using slow upward motions. Avoid deflating the batter, preserving its light texture for a fluffy, tender cake.
Sift flour with baking powder, then add gradually into the batter. Mix gently until smooth. Pour three quarters into the pan, keeping the remaining portion aside.
Combine cocoa powder with the reserved batter and mix thoroughly. Pour the cocoa mixture over the plain batter, then swirl gently with a fork to create marbling.
Bake for forty to forty‑five minutes. Test with a toothpick for doneness. Cool ten minutes in the pan, then transfer to a rack and slice when ready.