White chocolate, raspberry and coconut gateau

Ingredients

For the cake

80g unsalted butter, plus extra for greasing
1 x 9g tube freeze-dried raspberry pieces
150g Belgian white chocolate, broken into pieces
2 x 10g tubes Dr Oetker Gel Food Colour in Bright Red
1 tsp vanilla bean paste or vanilla extract
150ml soured cream
6 medium eggs
200g caster sugar, plus 2 tbsp extra for sprinkling
200g plain flour
½ tsp bicarbonate of soda

For the white chocolate frosting

1 x 200g bar Belgian white chocolate, roughly chopped
1 tbsp coconut oil
1 x 200g pack creamed coconut, grated coarsely
150g unsalted butter, softened
300g full-fat cream cheese
500g icing sugar, sifted

For filling and decoration

50g Belgian white chocolate, roughly chopped
edible red and pink heart confetti
1 tsp desiccated coconut
½ x 340g jar seedless raspberry jam (we like Hartley’s)
edible gold glitter spray
a few dried rose petals, optional

Step by step

Get ahead

The sponges can be made a day in advance, or frozen. The whole iced cake will last up to 5 days in the fridge.

Preheat the oven to 180°C, fan 160°C, gas 4. Grease and line a 23cm x 33cm Swiss roll tin with baking paper. You will need to make 2 rectangular cakes, one after the other (unless you have 2 identical tins), using half the cake ingredients in each.
Crush the freeze-dried raspberries (see tip, below) and reserve 1 tablespoon for later. Put 40g butter and 75g white chocolate in a heatproof bowl over a pan of simmering water and heat gently until melted. Remove from the heat and stir in 1½ teaspoons of food colouring from 1 tube (this will leave enough for the icing later), ½ teaspoon vanilla bean paste or extract, 2½ teaspoons crushed raspberries and 75ml soured cream.
Put 3 eggs and 100g caster sugar into a large bowl and whisk for 5-10 minutes, using an electric whisk until really thick and the mixture leaves a trail when the whisk is lifted. Sift in 100g flour, ¼ teaspoon bicarbonate of soda and a pinch of salt and fold in gently. Then fold in the chocolate mixture until smooth, trying not to knock out any air. Spoon into the tin, tilting it to get the batter right into the corners.
Tip Recipe photograph by Martin Poole
Bake in the oven for 18-22 minutes until just firm to the touch and starting to shrink at the edges. Put a large sheet of baking paper onto a clean work surface and sprinkle with 1 tablespoon sugar.
Meanwhile, make the chocolate disc decorations. Line a baking tray with baking paper. Melt 50g white chocolate (either in the microwave or in a bowl over a pan of simmering water) and transfer to a disposable piping bag. Snip off a 1cm opening and pipe at least 12 dots onto the paper, about 2cm wide and spaced apart. Carefully tap the tray on the worktop to spread the chocolate flat. Sprinkle the dots with a few heart confetti shapes, a little coconut and a pinch of the reserved crushed dried raspberries. Chill until set.
Once the cake is cooked, remove from the oven and carefully turn it out of the tin onto the sugar-dusted baking paper. Peel off the cake lining paper.
Using a serrated knife, carefully cut the cake down the middle, so you have 2 rectangles. Leave on the paper and cover lightly with a clean tea towel and allow to cool.
Repeat steps 1-7 (except step 5) to make another cake. While the cakes are cooling, make the frosting. Put the chocolate and coconut oil in a heatproof bowl over a pan of simmering water and heat, gently, until melted (you could do this in the microwave).
Put the creamed coconut and 3 tablespoons boiling water into a large bowl. Gently stir until smooth. Add the butter and whisk with an electric hand whisk until light and fluffy. Whisk the cream cheese until smooth then beat into the coconut and butter, gradually adding the icing sugar until really light and fluffy. Stir in the white chocolate mixture until smooth.
You need to divide up the frosting. Spoon 500g into a bowl (this is for the filling and crumb layer), put 75g into a disposable piping bag and sit it in a glass (for the decoration), and spoon another 225g into a bowl (this is for the top). Now divide the remaining frosting between 2 more bowls. Using the leftover food colouring, colour one half pale pink (about 4 drops of colouring) and the other bowla darker shade of pink (about 12 drops of colouring). Put them all in the fridge to chill and firm up.
To assemble, spread all 4 sponges with a little raspberry jam, you want a thin layer. Then, using the reserved filling frosting, spread a generous amount over the top, right to the edges. Gently lift the cake off the paper to ensure it has not stuck. Take one section of sponge and, starting from the short side, roll up tightly, using the paper to help you. Take the second sponge and join it where you finished the first, then continue to roll. Repeat with the remaining sponges to make a giant, fat Swiss roll.
Sit the rolled sponge upright on a cake plate. Spread a thin layer of the frosting all over the top and sides of the cake (this collects all the loose crumbs). Chill in the fridge for 30 minutes or until set.
Once set, use the dark pink frosting and spread from the bottom up, about 5cm high. It can be quite rough. Now repeat with the pale pink frosting, starting from the top of the dark pink, for another 5cm. Finally, spread the white frosting, kept for the top, to cover the top completely and to come down the side of the cake to meet the pale pink icing. Smooth the top with a palette knife. Clean the knife, then holding it flat against the side of the cake, turn the plate to smooth the icing; the colours should gently smudge together.
Cut off a 3cm opening from the piping bag and pipe 12 balls of frosting all around the rim of the cake on the top, with gaps in between. Chill for 30 minutes before finishing off.
To finish, lightly spray the top, just around the edge, with the gold spray. Then sprinkle with the remaining crushed freeze-dried rasperries from the reserved tablespoon and the rose petals, again just around the edge. Remove the chocolate discs from the paper and arrange in between the icing balls.
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