Dobos torte

This showstopper does take a bit of time and effort, but the result is spectacular.

CUTS INTO 14 SLICES PREP 1½hr, plus cooling and chilling COOK about 30min

FOR THE BUTTERCREAM

• 400g granulated sugar

• 200ml double cream

• 350g salted butter, softened, plus extra to grease

• 75g dark chocolate, melted and cooled

FOR THE CAKE

• 10 medium eggs, separated, plus 2 medium egg yolks

• 400g caster sugar

• 1tbsp lemon juice

• 1tbsp vanilla extract

• 100g ground hazelnuts

• 100g plain flour

TO DECORATE

• Hazelnut-caramel shards, optional 1 Start with buttercream. Over a gentle heat, in a large pan, heat sugar and 100ml water, stirring until sugar dissolves. Turn up heat and boil until it forms a dark golden caramel. Remove from heat and whisk in cream (it will froth up). Set aside to cool.

2 Using a freestanding mixer (or handheld electric whisk and a large bowl), beat butter until light and fluffy. Add caramel a splash at a time, beating well after each addition. Put ⅔ of buttercream into a piping bag (or transfer to a separate bowl). Fold cooled chocolate into remaining buttercream, transfer to a second piping bag (or leave in bowl) and set both aside in a cool place.

3 Preheat oven to 200°C (180°C fan) mark 6. Grease a 23 x 33cm Swiss roll tin; line with baking parchment. For the cake, with handheld electric whisk or freestanding mixer, beat 12 egg yolks and sugar until pale and thick, about 5min. Add lemon and vanilla; beat for 1min. Add ground hazelnuts and ½tsp fine salt. Beat to combine. Use a large metal spoon to fold in flour in 2 batches.

4 In a separate large bowl with a clean whisk, beat 10 egg whites to stiff peaks. Add a few spoonfuls of egg white to yolk mixture and stir well to loosen it, then gently fold in remainder of whites with a large metal spoon. Pour ½ the batter into prepared tin and level with a palette knife. Bake for 10min, or until sponge is firm and golden.

5 Using parchment paper, lift sponge on to a wire rack to cool. Line tin with fresh baking parchment. Bake remaining batter as before.

6 Once sponges are cool, with a long side closest to you, cut each sponge vertically into thirds. Lay a sponge on a serving plate then pipe or spread 1/5 of the chocolate buttercream on top in an even layer. Repeat 4 times more (to use all chocolate buttercream) then lay on final sponge. Trim edges. Gently spread a thin layer of caramel buttercream over top and sides of cake (a crumb coat). Chill for 30min.

7 Spread remaining caramel buttercream over top and sides of cake and smooth with a palette knife dipped briefly in hot water. Chill for 20min then top with hazelnut-caramel shards, if you like.

TO STORE Cover and chill cake without shards for up to 3 days. Allow to come to room temperature before serving.

TO DECORATE Make a dry caramel in a frying pan, then pour on to a lightly greased baking sheet and scatter over blanched hazelnuts. Cool, then break into shards.

PER SERVING: CALS 635; FAT 38G; SAT FAT 20G; CARBS 67G