Toasted hazelnut & mixed berry roll

Preheat the oven to 180°C, gas mark 4. Grease and line a 33x23cm baking tin, then lightly grease the baking parchment. Blitz the nuts to fine crumbs in a food processor.

Put the egg yolks and caster sugar in a large bowl and beat with an electric hand mixer at high speed for 2-3 minutes, until pale and thickened. Sift in the flour, add the hazelnut crumbs and fold in.

Using clean beaters, whisk the egg whites to soft peaks in another bowl. Gradually and gently fold the whites into the sponge mixture. Pour into the tin and bake for 15 minutes until golden and springy to the touch.

Put a large sheet of baking parchment on the work surface and sprinkle it with a little caster sugar. Carefully turn the sponge onto the paper and peel the parchment from its base. Leave to cool completely.

Beat the mascarpone, vanilla extract and icing sugar together, then spread over the sponge. Sprinkle with 125g fruit. Using the sugar-dusted paper to help, roll the sponge tightly, starting from the long side. Place on a serving board and dust with more icing sugar. Serve sliced, with more berries on the side.