The secret to this incredibly light cake is relying on heavily whipped eggs rather than heavy fats. It creates an airy, delicate texture that bakes in just seven minutes. You'll roll the warm sponge right out of the oven, which prevents cracking and sets the shape for whatever filling you choose. With a rich cocoa flavor and a tender crumb, it's a surprisingly simple weekend baking project that looks straight out of a bakery window.
Prep
20 min
Cook
10 min
Total
1 hr 20 min
Servings
8
Course
Dessert
Ingredients
75g caster sugar
3 eggs
1 teaspoon vanilla bean paste or extract
75g plain flour
25g cocoa powder
½ teaspoon baking powder
25g unsalted butter, melted and cooled slightly
100g unsalted butter
200g icing sugar, sifted
1 teaspoon vanilla bean paste
2 tablespoons milk
200g dark chocolate, chopped
15g unsalted butter
1 heaped teaspoon golden syrup
50g white chocolate, chopped
40 x 26cm Swiss roll tin
Instructions
1Preheat the oven to 180C (160C fan or gas mark 4). Grease a 40 by 26cm Swiss roll tin and line it with buttered baking parchment.
2Combine the caster sugar, eggs, and vanilla extract in a large mixing bowl. Whisk on high speed for 2 minutes until the mixture turns pale, triples in volume, and leaves a thick ribbon trail when you lift the whisk. Getting enough air into the eggs here is what gives the sponge its lift.
3Sift the plain flour, cocoa powder, and baking powder into the bowl. Gently fold everything together using a large metal spoon or rubber spatula, taking care to keep the air in the batter.
4Just before the dry ingredients are fully mixed, pour the slightly cooled melted butter around the edge of the bowl and fold it in completely.
5Pour the batter into your lined tin. Spread it gently into the corners without deflating the airy mixture.
6Bake for 7 minutes until the sponge springs back when touched. Let it cool in the tin for 5 minutes, then turn it out onto a fresh piece of baking parchment.
7Peel off the original baking parchment from the top of the cake and trim the short edges to make them neat.
8Start at the long edge closest to you. Use the fresh parchment paper to roll the warm sponge tightly, keeping the paper rolled inside. Set it aside to cool completely before unrolling to add your filling. Rolling it warm trains the cake's shape and prevents cracking.
Notes
Timing: Set a strict timer when baking the sponge. Even one extra minute in the oven dries out the cake and causes it to crack when rolling.
Filling: If adding buttercream later, make sure it's slightly softer than usual so it spreads easily without tearing the delicate sponge.
Equipment: A 40 by 26cm Swiss roll tin is ideal, but any similarly sized rimmed baking sheet will work.