Gianduja and affogato mousse cake

1.For hazelnut cake, preheat oven to 180°C. Grease two 28cm x 33cm Swiss roll tins and line with baking paper. Meanwhile, blend hazelnuts, 150gm caster sugar and plain flour in a high-speed blender, pulsing until hazelnuts are fine and sugar is powdered. Set aside. Whisk egg whites, remaining 150gm caster sugar and a pinch of salt in the bowl of an electric mixer until firm peaks form (6-8 minutes), add yolks and whisk until thick and mixture holds a trail when the beaters are lifted (3-4 minutes). Fold in hazelnut mixture and butter. Spread mixture evenly into prepared tins, smooth top and bake, rotating the tins halfway through cooking, until lightly golden and cakes springs back when lightly pressed (8-10 minutes). Turn out onto baking paper lightly dusted with flour, remove backing paper and set aside to cool (30 minutes).

2.For affogato mousse, heat liqueur, coffee and 80ml boiling water in a small saucepan, stirring to dissolve coffee. Meanwhile soften gelatine in a small bowl of cold water (3-5 minutes). Squeeze out excess water and stir gelatine into coffee mixture until dissolved, then add white chocolate and stir until smooth. Remove pan from heat and cool to room temperature. Once cool, gently stir white chocolate mixture into mascarpone with a spoon taking care not to over mix. Whisk cream with an electric mixer to almost firm peaks, then fold through affogato mixture. Refrigerate for 1 hour to thicken slightly but not longer as you don’t want it to set.

3.Meanwhile, for gianduja layer, bring cream to a simmer in a small saucepan over medium heat. Remove pan from heat, add chocolate, cover with a lid and stand until chocolate melts (5 minutes). Whisk to combine completely.

4.To assemble, grease a 10.5cm deep, 11.5cm x 27cm loaf tin and line base and sides with baking paper, extending paper 5cm beyond tin rim. Using the shape of the tin as a guide, trim cake into four rectangles the same size as the tin. (If the tin sides slope you will need to account for this by cutting each layer slightly larger). Place a layer of cake in the base of the tin, then spoon over slightly less than a quarter of the gianduja layer. Freeze for 5 minutes, then top with one-third of the affogato mousse. Repeat layering with remaining ingredients finishing with a thicker gianduja layer. Refrigerate to set (8 hours or overnight).

5.Serve cut into slices scattered with toffee shards and extra hazelnuts.