Napoleon Cake

Method

1. 01

   Step 1: Make the quick pastry

   Mix the flour and salt, grate in the cold butter on the coarse side of a box grater and rub it in with your fingertips until it looks like coarse crumbs. Beat the egg with the ice-cold water and vinegar, pour it over and bring everything together into a ball without kneading — you should still see flecks of butter. Divide into 8 balls of about 110 g, wrap and chill for 30 minutes.

2. 02

   Step 2: Cook the custard

   In a saucepan, whisk the eggs, sugar and flour with 200 ml of the cold milk until smooth. Heat the rest of the milk until steaming and pour it into the egg mixture in a thin stream, whisking all the time. Return to medium-low heat and keep whisking until the custard is as thick as sour cream and the first bubbles break the surface, then cook 2 minutes more. Stir in the vanilla, press cling film onto the surface and cool to room temperature.

3. 03

   Step 3: Roll out the rounds

   Heat the oven to 200°C (400°F). Roll each ball on a sheet of baking paper as thin as you can, 1–2 mm, then lay a 24 cm plate on top and cut around it, leaving the trimmings in place. Prick the round all over with a fork so it bakes flat.

4. 04

   Step 4: Bake the layers

   Slide the paper onto a baking sheet and bake for 7–9 minutes, until evenly golden with slightly darker edges. The trimmings bake alongside and become the crumb coating. Cool the layers flat; they are fragile while hot, so don't stack them straight away.

5. 05

   Step 5: Finish the custard

   Beat the soft butter for 3–4 minutes until pale and fluffy. Add the cooled custard a spoonful at a time, beating well after each. Both need to be at the same room temperature, or the cream may split.

6. 06

   Step 6: Assemble the cake

   Set aside about a fifth of the cream for the top and sides. Stack the layers on a serving plate, spreading each one generously with cream and pressing lightly with your palm. Cover the top and sides smoothly with the reserved cream.

7. 07

   Step 7: Coat and chill

   Crush the baked trimmings into fine crumbs with a rolling pin or in a blender and press them all over the top and sides. Chill for at least 8 hours, ideally overnight, so the crisp pastry turns tender and the cake slices cleanly.