Ingredients

Step by step

1. For the ice cream, blitz the chestnut purée and condensed milk together with a stick blender, until smooth. In a separate bowl, whip the cream until it reaches soft peaks. Add the chestnut mixture and the vanilla, and beat again, until the soft peaks form. Transfer to a lined loaf tin and freeze for 1½ hours until fairly firm.
2. Meanwhile, preheat the oven to 200°C, fan 180°C, gas 6. Line a 24cm x 32cm Swiss roll tray with baking paper, making sure that it comes 4cm above the sides of the tray.
3. In a large bowl, beat the eggs, vanilla and sugar with an electric whisk for 6-8 minutes, until the mixture is light and creamy, and thick enough to leave a ribbon-like trail. Sift over half the flour and, using a large metal spoon, very carefully fold through the flour, so that no traces remain. Repeat with the remaining flour.
4. Pour into the prepared tray and gently smooth out with the back of the spoon. Bake for 12-15 minutes, until the sponge is golden, well-risen and springy. Meanwhile, place a sheet of baking paper on your work surface and dust with sugar. Turn the sponge out onto the sugared paper, carefully peel away the lining paper, then, starting from one of the long edges, use the sugared paper to roll up the sponge tightly, with the paper inside. Transfer to a cooling rack to cool completely.
5. Remove the ice cream from the freezer (it should be soft but able to hold its shape). Scoop it out onto another sheet of baking paper and roll it into a sausage shape, the same length as the sponge. Twist the ends like a cracker and freeze for a further hour.
6. To assemble the roll, mix the Christmas pudding and apricot jam together until it forms a rough paste. Carefully unroll the sponge and spread the mixture over evenly. Peel the paper away from the ice-cream log and lay it in the centre of the sponge, then gently re-roll the sponge to encase the ice cream. Freeze, seam-side down, for a further 2 hours, until completely set.
7. To serve, trim the ends and cut into slices.