- 3 eggs
- 185g Low GI sugar
- 25g cocoa powder
- 110g plain flour
- 2 Tbsp cornflour
- 250ml warm milk
- 2 Tbsp vegetable oil
- 75g unsalted butter
- 1 tsp natural vanilla extract
- ½ cup raspberry jam, sieved
1 Preheat oven to 180°C. Combine the eggs, 125g sugar and cocoa in the bowl of an electric mixer and beat with the whisk attachment on high speed for 10 minutes, until very foamy and firm.
2 Sift 90g flour on top and fold in very gently. Add 50ml milk and the oil, stir gently, then spread onto a lined 33cm x 23cm Swiss roll pan. Bake for 10 minutes, until lightly golden, then invert onto a biscuit tray dusted with the cornflour, remove the baking paper, cover with a tea towel and set aside to cool.
3 Combine the remaining flour with 1 Tbsp butter in a small saucepan and cook over a low heat for 3 minutes, until crumbly. Whisk in the milk, vanilla and remaining sugar, then cook, whisking constantly, until a smooth sauce forms. Set aside to cool completely.
4 Put the remaining butter in the bowl of an electric mixer and beat with the whisk attachment on high speed until very light. Add the milk sauce in a steady stream, then continue beating for 5 minutes, until smooth and firm.
5 Cut the sheet cake in half lengthways and trim the edges. Spread each half with mock cream, then jam and roll up. Cut into lengths.