Tiramisu roulade

Instructions

1. Preheat the oven to 180°C, fan 160°C, gas mark 4. Line a 20cm x 30cm swiss roll tin with baking paper.
2. In a large mixing bowl, whisk the egg whites until foamy, then add the cream of tartar with a pinch of salt and continue to whisk until the mixture is stiff and forms peaks that hold their shape when the beaters are removed.
3. Sift the flour, 2 tablespoons cocoa and sugar over the egg white mixture, then gently fold until smooth and combined.
4. Spoon the batter into the prepared tin and smooth the surface with a spatula. Bake for 12-15 minutes or until the sponge feels firm and springy to the touch.
5. Lightly dust a sheet of baking paper with 1 teaspoon cocoa powder. Turn the cake out onto the baking paper, discarding the sheet from the tin, then roll up the roulade from one short side, with the cocoa-dusted paper inside as you roll. Set aside to cool.
6. Put the coffee granules in a mixing bowl, add 1 teaspoon boiling water and stir to dissolve. Add the icing sugar and quark, and mix until smooth and combined.
7. Unroll the sponge and drizzle over the Marsala wine, then spread over the quark mixture. Scatter over half of the grated chocolate and re-roll the sponge without the paper. Scatter the remaining chocolate over the top of the roulade and cut into slices to serve.