400 grams salted caramel spread [I used the Tiptree one]
4 large bananas, peeled, in 1 centimetre slices
600 millilitres double cream, whipped to soft peaks
20 grams dark chocolate, chilled
20 centimetre square serving dish
Make the custard: Put the milk into a saucepan and bring it to the boil, then take it off the heat and let it cool for a few minutes.
Meanwhile, put the egg yolks and sugar into a large mixing bowl and whisk them together, then add in the flours and vanilla and mix them through. Tip the hot milk into the egg mix, mix it all together then return the whole mixture to the saucepan over a low heat. Use a whisk to stir constantly while you bring it to the boil. Once the custard has reached a boil and thickened, remove it from the heat and put it into a jug. Put clingfilm right on top of the custard to stop it forming a skin, seal it around the edge of the bowl, and chill for 1 hour.
Assemble the pudding: First, if the caramel spread is quite thick, warm it gently in a saucepan so that you can pour it into the pudding dish.
Arrange 16 digestives in a layer on the bottom of the dish then pour in half of the caramel and smooth it over. Slice the bananas and place a layer of them on top of the caramel, then top with the chilled custard and smooth it over.
Place another layer of biscuits on top of the custard, followed by more caramel and a second layer of banana slices. Top with the whipped cream, then finish with a thick layer of finely grated chocolate. Leave in the fridge for 2 hours before serving.