Prinsesstårta

Step 1: Make the custard first. Heat 1 ¾ cups whole milk with 1 vanilla pod (seeds scraped in, pod too) in a pan over a medium heat until steaming. In a bowl whisk 4 egg yolks, 2 ½ oz caster sugar and 1 ¼ oz cornflour until pale.

Step 2: Pour the hot milk onto the yolks in a thin stream, whisking all the time, then return everything to the pan. Cook over a medium-low heat, whisking constantly, until it bubbles and turns very thick, like mayonnaise; let it bubble for a full minute so the cornflour sets properly.

Step 3: Off the heat, take out the pod and whisk in ⅔ oz unsalted butter. Press cling film onto the surface and chill for at least 2 hours, until firm.

Step 4: For the sponge, heat the oven to 350°F (300°F fan) and line a 23 cm springform tin with baking paper. Whisk 4 eggs and 5 ½ oz caster sugar with an electric mixer on high for 8–10 minutes, until pale, tripled in volume and a ribbon trailed from the whisk sits on the surface for 3 seconds.

Step 5: Sift 2 ⅛ oz plain flour, 2 ⅛ oz potato starch and 1 tsp baking powder over the eggs and fold in gently with a large metal spoon, cutting down through the middle and turning the bowl, until no flour pockets remain.

Step 6: Pour into the tin and bake for 30–35 minutes, until golden, springy and shrinking slightly from the sides. Do not open the oven in the first 20 minutes or the sponge will sink. Cool completely in the tin.

Step 7: Whip 2 cups double cream with 4 ½ oz mascarpone and 2 tablespoons of 1 ¾ tbsp icing sugar to firm, smooth peaks. Stop the moment it holds its shape; over-whipped cream turns grainy and weeps, the classic way this cake collapses.

Step 8: Slice the sponge horizontally into three thin layers. Put the bottom layer on a serving plate and spread with 5 ½ oz raspberry jam, then with half of the custard.

Step 9: Add the second layer, spread with the rest of the custard and 3–4 tablespoons of cream. Top with the third layer.

Step 10: Pile the remaining cream on top and smooth it into a high dome with a palette knife, filling the edges so the sides slope down to the plate. Chill for 30 minutes.

Step 11: Dust the worktop with the rest of 1 ¼ tbsp icing sugar and roll 14 oz green marzipan into a thin circle about 38 cm across. Lift it over the rolling pin and drape it over the dome. Smooth the top with your palms, ease the sides down without pleats and trim the base.

Step 12: Dust lightly with more icing sugar and set 1 pink marzipan rose on top. Chill until serving and slice with a hot, dry knife.