Heat the oven to 220C/200C fan/gas 7. Line a 22 x 32cm swiss roll tin (if it’s 20 x 30cm that’s still fine) with baking parchment. Sift the flour and cocoa powder together into a bowl and set aside.

Crack the eggs into another bowl or the bowl of a stand mixer and tip in the sugar. Use an electric whisk or the whisk attachment to beat the eggs and sugar together for 5 mins until pale and very thick. Use a spoon or spatula to gently fold in the flour mixture until completely incorporated and everything’s the same colour with no streaks.

Gently scrape the mix into the tin and spread to the corners. Bake for 9-10 mins until puffed up and springy to touch. While the cake is baking, get another piece of parchment a little larger than the tin and scatter it with sugar. When the sponge is cooked, use oven gloves to carefully invert it onto the sugar-coated paper. Lift off the tin and peel away the top layer of parchment. Score a line 2cm from one of the shorter edges, then use the parchment to roll the sponge into a spiral with the parchment running through it. Leave the rolled sponge to cool completely.

While the cake is cooling, make the filling by whisking all the ingredients together until the cream stiffens. Unroll the sponge and spread over the filling, leaving the scored edge clear. Starting from the scored edge, use the parchment to roll the sponge up around the filling. Lift onto a board or serving platter and dust with icing sugar. Can be served straight away or chilled for up to 24 hrs. Serve in slices.