The Ultimate 5-Layer Chocolate Orange Cake with Peanut Crunch

Ingredients

1. Chocolate-orange sponge

• 50 g unsalted butter, softened
• 50 g caster sugar
• Finely grated zest of 1/2 orange
• 1 large egg
• 40 g self-raising flour
• 10 g cocoa powder
• 15 ml milk

2. Peanut crunch

• 50 g milk chocolate, divided
• 20 g smooth peanut butter
• 20 g roasted salted peanuts, finely chopped
• 15 g cornflakes or feuilletine, lightly crushed

3. Orange curd

• 80 ml freshly squeezed orange juice
• 15 ml lemon juice
• Finely grated zest of 1 orange
• 50 g caster sugar
• 1 large egg plus 1 egg yolk
• 40 g unsalted butter, cubed
• 2 g leaf gelatine

4. Milk-chocolate peanut mousse

• 120 g milk chocolate, finely chopped
• 80 g smooth peanut butter, at room temperature
• 80 ml whole milk
• 200 ml cold double cream
• 3 g leaf gelatine

5. Orange mascarpone cream

• 250 g cold mascarpone
• 300 ml cold double cream
• 30 g icing sugar, divided
• Finely grated zest of 1/2 orange
• 1 tsp vanilla extract

Caramel and decoration

• 50 g caster sugar
• 20 ml water
• 50 ml double cream, warmed
• 10 g butter
• Small pinch of salt
• Chopped roasted peanuts
• Orange-zest curls or well-drained fresh orange pieces

Method

1. Bake the sponge: Heat the oven to 180C conventional / 160C fan. Grease the tin and line the base. Beat the butter, sugar and orange zest until pale and fluffy, then gradually beat in the egg. Fold in the flour and cocoa, followed by the milk.
2. Spread the batter evenly in the tin and bake for 15-20 minutes, checking from 15 minutes. The centre should spring back lightly and a skewer should come out without wet batter.
3. Cool completely. Remove the baking paper and trim any dome to make a flat surface. Clean the tin, line the inside edge with the acetate collar and return the sponge to the bottom.
4. Make the peanut crunch: Melt 40 g of the milk chocolate, then stir in the peanut butter. Fold in the chopped peanuts and crushed cornflakes or feuilletine.
5. Spread the crunch over the sponge in an even layer about 4 mm thick without pressing it into a dense slab. Refrigerate for 20 minutes. Melt the remaining 10 g chocolate, spread it very thinly over the crunch and chill for another 10 minutes.
6. Make the orange curd: Soak the 2 g leaf gelatine in plenty of cold water for 5-10 minutes. Whisk the orange juice, lemon juice, zest, sugar, egg and yolk in a small saucepan.
7. Cook over a low heat, stirring continuously and scraping the bottom and corners, until it coats the back of a spoon and reaches about 82C. Do not let it boil.
8. Remove from the heat. Squeeze the water from the gelatine and stir it into the hot curd until dissolved. Stir in the butter, then pass the curd through a sieve.
9. Stir occasionally until the curd cools to barely warm, around 28-30C, while remaining spreadable. Spoon it gently over the chilled crunch and level the surface. Refrigerate for 2-3 hours until set.
10. Make the mousse: Once the curd is firm, soak the 3 g leaf gelatine in cold water for 5-10 minutes. Put the chopped milk chocolate and peanut butter in a heatproof bowl.
11. Heat the milk until steaming. Remove it from the heat, squeeze the gelatine dry and dissolve it in the milk. Pour over the chocolate and peanut butter, wait one minute, then stir until smooth.
12. Cool the chocolate mixture to about 32-35C while keeping it fluid. Whip the cold double cream to soft peaks. Stir a quarter of the cream into the chocolate mixture, then gently fold in the remainder in two additions.
13. Spoon the mousse over the set curd and smooth the top. Cover without touching the mousse and refrigerate overnight, ideally for at least 8 hours.
14. Add the mascarpone layer: On serving day, gently stir the mascarpone with 10 g icing sugar until just smooth. Separately whip the double cream with the remaining 20 g icing sugar, orange zest and vanilla to firm, smooth peaks.
15. Fold the whipped cream into the mascarpone in two or three additions. With the cake still in the tin, spread about 300 g over the mousse. Level it and chill for 2 hours. Refrigerate the remaining cream for decorating.
16. Make the caramel: Heat the sugar and water in a small saucepan until dissolved, then bubble without stirring until amber. Remove from the heat and carefully add the warm cream in stages. Stir in the butter and salt, then cool completely.
17. Decorate: Release the tin and carefully peel away the acetate while the cake is cold. Apply a thin coating of reserved cream around the sides, leaving some layers visible. Add a little cooled caramel around the top edge, testing one drip first.
18. Pipe the remaining cream into swirls and finish with chopped roasted peanuts, orange zest or well-drained orange pieces. Keep chilled until ready to serve.