Jelly & custard celebration cake

Preheat the oven to 180ºC, gas mark 4. Grease 3 x 20cm loose-bottomed sandwich tins and line the bases with baking parchment. For the cake, put the sugar and baking spread (or butter) into the bowl of a freestanding mixer and beat until pale and fluffy. (Alternatively, put everything in a large bowl and use an electric hand mixer.)

Add the eggs, 1 at a time, beating after each addition until completely incorporated. Once added, the mixture may look a little split, but that’s normal. Heat the milk in a small pan until hot. Add the hot milk, which may help bring the mixture back together. Don’t worry if it makes it look worse.

Sift the flour, custard powder, baking powder and ½ tsp fine salt into a bowl. Fold 1 / 3 of this into the egg mixture using a large metal spoon or spatula, then repeat twice more. Once you have a smooth batter, divide it between the cake tins as evenly as possible, then bake for 20-25 minutes, or until a skewer inserted into the centre of each cake comes out clean. Remove the cakes from the oven and allow to cool completely in their tins.

While the cakes bake, make the custard. Put the milk, 50g of the sugar and the vanilla pod and seeds into a medium saucepan and set over a medium heat. In a heatproof bowl, whisk together the egg yolks and the remaining 50g sugar, then add the custard powder and whisk until pale and the sugar is more or less dissolved. Increase the heat to high and allow the milk to come to a boil, then pour the milk onto the egg yolk mixture in a steady stream as you whisk constantly. Putting a damp tea towel underneath the bowl will keep it from rocking around while you whisk.

Once the milk is well combined with the egg mixture remove the vanilla pod, then pour it back into the pan, off the heat. Whisk vigorously and return to a high heat. Do not stop whisking, and ensure the whisk is touching the base of the pan at all times. Allow the custard to boil and thicken, then pour into a shallow bowl or plate and cover the surface of the custard directly with clingfilm or damp baking parchment. Allow to cool completely, then pop into the fridge.

For the frosting, dissolve the jelly crystals in 2 tbsp water and set aside. Put the egg whites into the bowl of a freestanding mixer fitted with a whisk attachment (or use a large heatproof bowl and an electric hand mixer). Put the sugar into a saucepan with 50ml water and stir over a low heat to dissolve, then turn the heat up to high. When the sugar syrup reaches 110ºC on a kitchen thermometer (I use an instant-read digital thermometer), set the mixer to a medium speed to start breaking down the egg whites.

Add the jelly mixture to the sugar and swirl in the pan to combine. Continue to heat the sugar and jelly mixture to 118ºC, then pour it over the egg whites in a thin, steady stream running down the inside of the bowl, with the mixer still on medium. Once all the sugar syrup has been incorporated, turn the mixer to high and beat for a good 10 minutes to make a stiff, glossy meringue. You can also beat in ½ tsp fine salt, if liked, but this is optional.

With the mixer still running on high speed, add the room temperature butter to the meringue 1 piece at a time, allowing each to incorporate before adding the next. This is a slow process, so enjoy it! As you add the butter, the mixture may deflate and look split and curdled, but be patient and keep going. Once you’ve added all the butter, it should start to thicken to a luscious pink buttercream. If it doesn’t, carefully heat the sides of the bowl with a chef’s blowtorch (or sit the bowl over a pan of just-boiled water) while beating. The heat should help the mixture to emulsify.

To assemble, place 1 layer of cake onto the cake card and sit it on a cake turntable, or cake stand – a little blob of buttercream helps to stick the cake in place. Fill the piping bag with some buttercream and pipe a ring of buttercream around the edge of the cake. Spread 3 tbsp of the raspberry preserve across the cake, inside the ring of buttercream. Return the cold custard to a mixing bowl and beat until smooth (this takes some elbow grease), then spread a generous layer on top of the jam, still keeping within the buttercream boundary. Top with a second layer of cake and repeat. You may have a little custard left over – it’ll keep under wraps in the fridge for 5 days. Top with the final cake layer, flat side facing up. Pop the cake in the fridge for 20 minutes for the buttercream to firm up.

Although not essential, I like to ensure the cake is even by taking a bread knife and trimming off the outside edge of the cake all the way around – just 0.5cm or so off the edge makes for a neater cake. Keep the knife straight and level as you cut. It doesn’t matter if the cake ends up more of a polygon than a perfect cylinder, because when you spread the icing on you can make it round again.

Spread a thin layer of buttercream over the sides and top to make a ‘crumb coat’ – using an angled palette knife and cake turntable makes it easier. Chill for 20 minutes to firm up, then spread the rest of the buttercream in a generous layer all over the sides and top of the cake. Get the icing as sharp and smooth as possible. I find a bench scraper or the base of a square cake tin helpful to get this as neat as possible. To create the messy crown effect on the rim, take small portions of buttercream on the end of the palette knife and pile them around the top edge of the cake. Smooth the top of the cake out first, shaving right up to the messy crown edge with the palette knife, then carefully smooth the sides. Pop the cake in the fridge to firm up for 20 minutes or so.

To finish, mix the gold lustre with the vodka or lemon juice to create a thick paste. Paint the top edge of the crown to make it gold, then you’re ready to serve. Carefully transfer the cake to a cake stand if using a turntable.