Is it a biscuit or is it a cake? Liam’s strawberry and custard jaffa cakes are definitely cake and they’re easier to make than you might think. Liam’s chosen hexagons for his versions, but you could use any shape cutter you like.
Make the jelly. Break the jelly into its cubes and place them in a small bowl. Pour over the boiling water and stir until the jelly is completely dissolved. Pour the jelly liquid into the lined shallow baking tray and refrigerate until set (about 30 minutes). Heat the oven to 180°C/160°C fan/350°F/Gas 4.
Make the sponge. In the bowl of a stand mixer fitted with the whisk attachment, whisk the eggs and sugar together for 4–5 minutes, until thick and mousse-like and the mixture leaves a ribbon trail when you lift the whisk. Remove the bowl from the mixer and gently fold in the flour and custard powder.
Pour the batter into the lined Swiss roll tin and smooth it evenly into the corners. Bake in the centre of the oven for 10–12 minutes, until golden and risen and just firm to the touch. Remove from the oven and leave to cool in the tray for a few minutes, then turn out onto a wire rack, remove the backing and leave to cool completely.
Once cool, use the 7cm hexagonal cutter to cut out 6 hexagons of sponge and place them on the cooling rack. Discard the trimmings (or eat them!).
Turn out the jelly onto a sheet of baking paper and peel off the baking paper. Using the 5cm hexagonal cutter, cut out 6 hexagons of jelly. Position one jelly hexagon centrally on top of each sponge so that the straight edges of the smaller hexagon are positioned parallel to the straight edges of the larger.
Make the topping. Melt the chocolate in a bowl set over a pan of gently simmering water. Remove from the heat, leave to cool slightly, then pour the chocolate over the top of the jelly and sponge, until completely coated. Refrigerate for about 10 minutes, until set.
To finish, melt the white chocolate in a bowl set over a pan of gently simmering water. Remove from the heat and spoon the mixture into the piping bag fitted with the plain nozzle. Remove the jaffa cakes from the fridge and pipe lines over the top of the darker chocolate. Leave to set completely at room temperature before serving.