Step 1

Preheat the oven to 200°C, gas mark 6 and grease and line a 20x30cm Swiss roll tin with baking parchment. You could also use a shallow baking tray. To make the roulade, melt the chocolate in a heatproof bowl set over a pan of simmering water. Separate the egg yolks and egg whites between two large bowls and add the sugar to the yolks.

Step 2

Use a handheld electric whisk to whip the egg whites into stiff peaks. Whisk the egg yolks and sugar (no need to clean the whisk) in the other bowl until pale and fluffy. The mixture should have a thick consistency that leaves a trail that holds its shape for 3 seconds when you lift the whisk out. Using a spatula, gently fold in the melted, slightly cooled chocolate and cocoa powder.

Step 3

Spoon a small amount of the stiff egg whites into the chocolate mixture and stir to combine. This loosens the mixture and makes it easier to incorporate the rest of the egg whites. Fold through the rest of the whites until they are well combined and no large white lumps can be seen in the mixture.

Step 4

Pour into the prepared tin and spread right into the edges. Sprinkle over the sesame seeds, then bake the roulade for 15-20 minutes until the top feels slightly crisp. Leave to cool completely in the tin.

Step 5

To make the caramel, heat the caster sugar in a medium, heavy-bottomed saucepan over a medium heat until it begins to melt and turns golden brown. When completely melted and the caramel is an amber colour, add the cream (it will bubble and splutter, so be careful), whisking constantly. If the caramel forms hard lumps, return to a low heat and stir gently until they have disappeared. Once smooth, add the butter, followed by the tahini and sea salt, and whisk until combined. Leave until completely cool, then chill before using.

Step 6

For the filling, whip the cream into soft peaks and lay out a sheet of baking parchment. Turn the roulade out onto the sheet and remove the layer of baking parchment. Score a line about 1cm from the short edge of the flat roulade. Spread the tahini caramel all over the top in one even layer using a palette knife or spatula, then spread the cream over the top.

Step 7

Roll up the roulade from the side with the scored line (don’t worry if it cracks, it’s part of the charm!) and keep refrigerated until ready to serve. Dust lightly with cocoa powder, if you like. The roulade is best eaten on the day it is made, but will keep in the fridge for 2-3 days.