Delight your dinner guests with these elegant tarts, made using rings of crisp, sweet shortcrust pastry, a light chocolate and hazelnut mousse and a layer of fresh raspberry jelly. Standing upright on a bed of hazelnut crumble, they are decorated with raspberries, tempered chocolate spheres and gold leaf.
For the pastry, tip the flour, icing sugar, ground almonds, salt and butter into a food processor and blitz to very fine breadcrumbs. Add the egg yolk and blitz until combined. Turn out onto a lightly floured surface and bring together to a dough. Wrap in cling film and chill for 30 minutes until firm.
For the chocolate mousse, line the sides of two 8cm tart rings with acetate, then place the lined rings on a strip of acetate. Soak the gelatine leaf in a bowl of cold water for 5 minutes to soften. Place the chocolate, praline paste and Frangelico in a large heatproof bowl set over a pan of gently simmering water. Heat gently, stirring, until the chocolate is melted, then remove from the heat.
Drain the gelatine leaf, squeezing out the excess water, then add them to the hot chocolate mixture, stirring to melt the gelatine. Leave to cool slightly, then stir in the egg yolk until well combined.
In a small bowl, whisk the egg white with the sugar until stiff peaks form, then gently fold into the chocolate mixture.
Divide the mixture between the two tart rings, level with a palette knife then chill for 1 hour until set.
For the raspberry jelly, line a 15cm x 10cm shallow tray with a sheet of silicone. Soak the gelatine leaves in a bowl of cold water for 5 minutes to soften.
Place the raspberries in a mini food processor and blitz to a puree. Pass through a sieve into a small pan, add the caster sugar and 2 tbsp water. Place the pan over a medium heat and bring the liquid to the boil.
Drain the gelatine leaves, squeezing out the excess water, and add them to the hot purée. Stir to melt the gelatine, then pour into the lined tray. Leave to cool then chill for 30 minutes until set.
On a lightly floured surface, roll the chilled pastry out to a rectangle approximately 9cm x 28cm and the thickness of a £1 coin. Cut out 4 strips each 2cm wide and use to line four 9cm pastry rings. Freeze for 20 minutes.
Heat the oven to 180°C/160°C fan/350°F/Gas 4 and blind bake for 10–12 minutes. Leave to cool, then turn out of the rings.
For the hazelnut crumb, tip the ground hazelnuts, flour, sugar and butter into a bowl and rub the mixture together with fingertips until the consistency of crumbs. Bake on a lined baking tray for 12–15 minutes until golden, stirring halfway through to ensure even baking. Remove from the oven and leave to cool.
For the chocolate decorations, melt 75g of the dark chocolate in a heatproof bowl set over a pan of barely simmering water and heat it up until it reaches 41°C/105.8°F. Remove the bowl from the pan, then stir in the remaining 25g of chocolate, until melted and stir until cooled to 32°C/89.6°F.
Lay a 15cm strip of acetate on the work surface and spray with gold spray, then spread the tempered chocolate on top in an even layer about 3mm thick. Leave for about 10 minutes, until almost set, then use the end of a piping nozzle to stamp out 8 rounds. Leave to set, then carefully peel off the discs.
To assemble the vertical tarts, remove the tart rings from the mousse and peel off the acetate. Cut each mousse in half, so that you have 4 semicircles. Place one semicircle inside each pastry ring so that the curved edge sits flush inside the pastry ring.
Cut four 8cm x 2cm strips of raspberry jelly and place a strip along each cut side of the mousse, so that when you stand the circles of pastry up, it is sitting on top of the mousse.
Arrange 4 small piles of hazelnut crumb on a serving plate and stand each tart up on top of the crumb, so they are standing vertically.
To decorate, lightly whip the cream to soft peaks and place in a piping bag. Snip off the end of the piping bag and pipe 3 small blobs of cream on top of the raspberry jelly. Place half a raspberry on top of each blob of cream then decorate with the chocolate spheres, gold leaf and hazelnut crumb.