Swedish Princess Cake

Heat the oven to 350°F. Line the bottom of an 8-inch round cake pan with parchment and grease the sides. Beat large eggs and granulated sugar until very pale and thick. Fold in all-purpose flour, cornstarch, baking powder, and fine salt, then fold in unsalted butter and vanilla extract just until smooth. Bake until the sponge is lightly golden and springs back when pressed, about 20 to 25 minutes. Cool completely, then split into 2 even layers.

To make the custard, whisk whole milk, large egg yolks, granulated sugar, cornstarch, and fine salt in a saucepan until smooth. Cook over medium heat, stirring constantly, until very thick and glossy. Remove from the heat and stir in unsalted butter and vanilla extract. Cool completely.

Whip heavy cream, mascarpone, powdered sugar, and vanilla extract together until thick and holding firm peaks.

Dust a clean work surface with powdered sugar and roll out ready-made marzipan into a large circle, about 12 inches across. Ease it into a mixing bowl and smooth it gently into shape.

Line the marzipan shell with some of the cream mixture, bringing it up the sides. Add one sponge layer, spread on raspberry jam, then add the custard. Top with the second sponge layer and cover the cake with the remaining cream mixture. Fold the ready-made marzipan over to seal, invert onto a serving plate, and chill before slicing.