Ingredients (serves 12)
For the orange jelly insert
- 2 gelatine leaves
- 200ml orange juice
- 10g caster sugar
For the sponge
- 5 large eggs
- 125g caster sugar
- 125g flour
For the soaking syrup
- 75g caster sugar
- 50ml water
- 30ml coconut rum
For the mousse
- 4 gelatine leaves
- 75g caster sugar
- 75g water
- 800g mango pulp from a can
- 400ml double cream
- 50g desiccated coconut
- 12.5cm/5-inch cake tin, greased and lined with cling film
- 30x20cm/12x8-inch Swiss roll tin, greased and lined with baking paper
- 2 x loose-bottomed 20cm/8-inch cake tins, greased and the bases lined with baking paper
- 20cm/8-inch cake ring
- 20cm/8-inch cake board or cake stand
Make the jelly insert: place the gelatine leaves, one by one, in a jug of cold water and allow to soak for 5 minutes. Heat the orange juice and sugar in a saucepan and bring to the boil, then squeeze the excess moisture out of the gelatine leaves and dissolve them in the hot orange juice. Pour this into the prepared cake tin and allow to cool, before transferring to the freezer to set completely.
Preheat the oven to 200°C/180°C fan/Gas 6.
Place the eggs and sugar in a large mixing bowl and whisk until very pale and fluffy. Using a handheld whisk, this will take about 10 minutes, or about 5–7 in a freestanding electric mixer with whisk attachment.
Sift the flour over the top of the whisked eggs and gently fold in using a spatula or large metal spoon. Pour at least two-fifths of this into the prepared Swiss roll tin, and divide the rest evenly between the cake tins. Bake all 3 for 8–10 minutes, or until the sponge springs back when gently touched. Allow to cool completely.
Make the soaking syrup by bring the sugar and water to the boil, then remove from the heat and stir in the coconut rum.
When the cakes have cooled, peel the paper from them. Take the cake baked in the Swiss roll tin and slice it lengthways into 3 strips about 5cm wide. Place the cake ring on the cake board, or directly on a cake stand, and place one of the two discs of cake in it. Dab on a little soaking syrup with a pastry brush.
Take one of the strips of cake and place it in the cake ring and against the side to create a wall. Put another strip next to it, and then, for the gap, slice off a piece from a third strip and pack that tightly between the other two, to create a continuous wall. Set to one side.
For the mousse, put the gelatine leaves, one by one, into a large bowl of cold water and allow to soak for 5 minutes. Boil the sugar and water, add the mango pulp, allow it all to come to a boil, then simmer until reduced by half. Remove from the heat. Remove the gelatine leaves from the soaking water and squeeze off the excess moisture, before adding them to the hot mango syrup. Mix well until dissolved. Allow to cool to blood temperature, before whipping the cream to soft, floppy peaks. Once whipped, gently pour the mango purée on to the whipped cream and fold it all together into a pale yellowish mixture. Fill the lined cake ring one-third full with the mousse.
Unmould the jelly disc and place it on top of the second disc of cake. Trim the cake so it is the same size as the jelly disc, then place this on the mousse layer, sponge-side down.
Pile more mousse into the cake ring so there is more than enough to fill it, then take a palette knife and gently drag the edges of the knife along the cake ring to smooth the mousse top. Sprinkle the desiccated coconut heavily over the surface.
Chill in the fridge overnight. To remove the cake from the ring, gently warm the sides with your hands, holding them in warm water beforehand if they are particularly cold, then gently lift the ring up and off.