Tamari

Heat the oven to 220C/200C fan/gas 7 and line a 22 x 32cm swiss roll tin with baking parchment. Sift the flour and cocoa powder into a bowl, then set aside. Crack the eggs into a second bowl, add the sugar and orange zest, and beat using an electric whisk for 5 mins until pale and very thick. Gently fold in the flour mixture using a spatula until no streaks of flour remain.

Gently scrape the mixture into the tin and spread out to the edges. Bake for 7-8 mins until springy. Meanwhile, lay a sheet of baking parchment slightly larger than the tin on a work surface and sprinkle over a layer of sugar. Invert the baked sponge onto the sugar-coated parchment, lift off the tin and peel away the top layer of parchment. Score a border 2cm from one of the shorter edges using a sharp knife, then use the sugar-coated parchment to help you roll the sponge up into a spiral, with the baking parchment inside. Leave to cool.

For the filling, whisk the cream, icing sugar and orange zest together to stiff peaks. Carefully unroll the sponge and spread over the jam or marmalade, followed by the cream filling, leaving the scored border clear. Starting from the scored edge, use the parchment to help you roll the sponge up around the filling, then discard the parchment.

Melt the chocolate in short bursts in the microwave. Put the swiss roll on a wire rack over a tray, then pour over the melted chocolate, using a palette knife or spatula to ensure it’s fully covered. Chill until the chocolate is set, then serve in slices.