For the pastry cream:
16 oz whole milk
4 oz sugar
2 teaspoons vanilla bean paste or vanilla extract
3 1/2 tablespoons cornstarch
4 egg yolks
1 oz unsalted butter
For the jam:
6oz jam sugar
For the sponge:
4 large eggs
5 1/2 oz granulated sugar
2½ oz cornstarch
2½ oz plain flour
1 tsp baking powder
1¾ oz butter, melted
For the fondant rose:
Pink fondant or modeling chocolate
For whipped cream:
2 cups heavy cream
4 Tbsp sugar
For the decoration:
1¾ oz dark chocolate, melted
For the marzipan:
14oz ground almonds
5½ oz caster sugar
9 oz powdered sugar
2 eggs, beaten
1 tsp almond extract
Americolor electric green food coloring gel (do not use liquid food coloring)
To make the pastry cream:
Pour 13 ounces of the milk into a saucepan. Add 2 ounces of the sugar and the vanilla bean paste to the milk. If using vanilla extract, stir it into the pastry cream after it is removed from the heat. Place the saucepan on medium heat and bring to a low boil. While the milk is heating, in a separate bowl, combine the cornstarch and remainder of the sugar. Stir until well combined. Add the remaining 3 ounces of milk and the egg yolks to the sugar and cornstarch mixture. Pour half of the boiling milk into the cornstarch mixture, and then quickly pour the egg-milk mixture back into the saucepan. It is important to bring the egg mixture up to the temperature of the milk so that the eggs don’t scramble.
Using the whisk, gently stir the egg-milk mixture over medium heat as it thickens, then whisk
briskly until smooth. Cook for 1 minute once the mixture has thickened. Remove from heat.
Add the butter and the vanilla extract, if using. Transfer to a bowl, cover the surface with saran wrap to prevent a skin forming and chill in the fridge until set (about 4 hours).
To make the jam:
Put the raspberries into a deep saucepan with the sugar and two tablespoons of water. Cook gently over a low heat, stirring occasionally, until the sugar is dissolved. Bring the mixture to the boil and boil vigorously for about 6-8 minutes and slightly thickened, or until the temperature reaches 219F on a sugar thermometer. Transfer to a heatproof bowl and leave to cool completely.
To make the sponge cake:
Preheat the oven to 350F. Grease and line the base of a 9-inch springform pan with parchment paper
Whisk together the eggs and sugar in a large bowl until the mixture is very pale and thick and the whisk leaves a trail on the surface when lifted. This will take about five minutes.
Sift the cornstarch, flour and baking powder over the egg mixture and carefully fold in using a large metal spoon. Fold in the melted butter, taking care not to over mix.
Pour the mixture into the lined pan and bake for 25-30 minutes until the sponge is golden-brown and has just started to shrink away from the sides of the tin. Remove from the oven and set aside to cool. When cool enough to handle, turn out on to a wire rack to cool completely.
Make a fondant rose using the method you prefer. I made mine out of modeling chocolate.
To assemble the cake:
Using a serrated knife, cut the cake horizontally into three even layers. Reserve your thinnest sponge cake layer for the top of the cake.Place one of the sponges onto a serving plate. Spread the jam over the base of the first sponge.
Spread half the pastry cream on top of the jam. Place the second sponge cake layer on the cake and spread the other half of the pastry cream evenly over it.
In a clean mixing bowl, whip heavy cream and sugar to firm peaks. Use most of the whipped cream (reserve about 1 cup for crumbcoating), to begin to create the dome shape at the top of the cake. First, spread the whipped cream evenly over the cake (you will have about a 1 1/2"-2" layer of whipped cream) then begin to angle the whipped cream mound inward with your spatula to form the rounded shape. This doesn't have to be perfectly domed because now you are going to cap the whole thing off with the third cake layer. Gently mold the cake on the top to create the shape you want.
Give the whole cake a thin layer of whipped cream crumb coat. Chill for one hour to firm up.
For the marzipan:
Mix the ground almonds and sugars in a mixer fitted with a dough hook, before adding the eggs and almond extract.
Knead in the bowl until it forms a stiff dough. Add 1-2 drops of electric green food coloring and knead to an even pastel green color.
Roll out the marzipan on a surface lightly dusted with cornstarch, to a 16in diameter circle, large enough to cover the cake. Lift the marzipan up over the cake and using your hands, shape the marzipan around the sides of the cake to get a smooth finish. Trim any excess.
Fit a piping bag fitted with a small star nozzle and pipe the remainder of the whipped cream around the base of the cake.
Spoon the melted chocolate into a small paper piping bag. Snip off the end and pipe circles over the top of the cake. Top with the fondant rose.
Note: The pastry cream, jam, fondant rose and marzipan can all be made the day before.