Ponche segoviano

Step 1: For the custard, heat 2 cups whole milk with 1 strip lemon peel until steaming. Whisk 4 egg yolks, 3 ½ oz caster sugar and 1 ⅜ oz cornflour in a bowl, pour in the hot milk while whisking, then return to the pan.

Step 2: Cook over a medium-low heat, whisking constantly, until it bubbles and thickens like mayonnaise, then cook 1 minute more. Remove the peel, press cling film on the surface and chill for at least 2 hours.

Step 3: Heat the oven to 350°F and line a 30 × 40 cm baking tray with baking paper. Whisk 5 eggs and 5 ½ oz caster sugar with an electric whisk for 8–10 minutes, until tripled in volume, pale and leaving a ribbon trail.

Step 4: Fold in 5 ½ oz plain flour in three additions with a large metal spoon, cutting through gently. A common mistake is stirring: the air is lost and the sponge bakes flat and rubbery.

Step 5: Spread the batter evenly on the tray and bake for 10–12 minutes, until golden and springy when pressed. Cool, then cut into three equal rectangles.

Step 6: Boil 2 ⅛ oz caster sugar and ½ cup water for 2 minutes, cool, and stir in the liqueur or orange juice if using.

Step 7: Lay one sponge layer on a board, brush with syrup and spread with half the custard. Repeat with the second layer and the rest of the custard, then top with the third layer and brush it with syrup.

Step 8: Roll 10 ½ oz marzipan on a surface dusted with ⅝ oz icing sugar to about 3 mm thick and lay it over the top and sides of the cake, trimming the base. Dust the top thickly with the rest of 1 ½ oz icing sugar.

Step 9: Heat a metal skewer over a gas flame until glowing, then press it on the sugar to brand a diagonal lattice, reheating it every line. A kitchen blowtorch, used briefly along a ruler, is a fine alternative. Chill for 1 hour before slicing.