Mix the cocoa powder with 1 tbsp boiling water to make a paste – this will help bring out the chocolatey flavour. Put the eggs, milk and oil in a large jug or bowl with a pinch of salt, and whisk until smooth. Tip the flour and sugar into a separate bowl and whisk in half the wet ingredients until smooth, then add the other half and mix. Whisk in the bloomed cocoa mixture – it should be a similar consistency to single cream. Set aside for 30 mins.

Brush a 25cm crêpe or non-stick frying pan with a little oil. Pour in around half a ladle of batter, then swirl around the pan to make a thin crêpe. After a minute, flip over and cook on the other side. Set aside on a plate. Repeat with the remaining batter until you have a stack of crêpes. Leave to cool.

To make the custard filling, warm the custard in a saucepan over a low heat, then stir through the chopped chocolate. In a small jug, mix the cornflour with a 2-3 tbsp of the custard mix, then whisk this back into the pan and bring to a simmer, whisking continuously. Pour into a bowl, cover and chill for 1 hr 30 mins. Mix the custard with a spoon to loosen, then lightly whip the cream and fold into the custard.

Layer the crêpes on a plate or cake stand using a thin, even layer of custard between each until you’ve used up the crêpes. Chill for at least 1 hr. Will keep chilled for 24 hours.

If making the sauce, coarsely grate the chocolate into a bowl. Warm the cream in a small pan over a medium heat until steaming. Remove from the heat, add the chocolate, golden syrup and a pinch of sea salt, and whisk until smooth.

For the topping, beat the cream, vanilla and sugar together in a large bowl or using a stand mixer until it reaches soft peaks.

Remove the cake from the fridge and pile the cream on top. Top with the chocolate sauce, caramel sauce, nuts and broken biscuits. Will keep covered and chilled for three days.