Sour cherry, pistachio and cardamom bakewell tart

Method

1. Mix together the cherries, icing sugar and sour cherry molasses in a bowl. Leave to macerate while you prepare the pastry.
2. Heat the oven to 180°C/160°C fan/gas 4. Tip the oats onto a baking tray and toast in the oven for about 10 minutes until golden, stirring every few minutes as they can burn quite quickly. Set aside to cool, then transfer to a food processor and whizz to a fine powder. Add the flour, icing sugar, salt and butter, then pulse to a sandy texture. Pulse in the egg to bring the mixture together into a dough, then tip out, form into a disc, wrap and leave to rest in the fridge for 1 hour.
3. Grease and flour the tart tin. Roll out the dough between 2 sheets of baking paper, then transfer to the tart tin, leaving a few centimetres of overhang all the way around, pushing it gently into the flutes. Prick the base several times with a fork, then put the tin in the fridge for 30 minutes.
4. Heat the oven to 180°C/160ºC fan/gas 4. Put a sheet of baking paper or foil over the pastry in the tart tin and mould it to the same shape. Fill with baking beans or uncooked rice, then blind-bake for 12 minutes. Remove the beans/rice and baking paper/foil and bake for 5 more minutes, then take out to cool. Once cooled slightly, use a small serrated knife to carefully trim off the pastry overhang.
5. To make the frangipane, whizz the pistachios to a fine powder in a food processor. Beat the butter and sugar together until light and creamy, then whisk in the egg and stir in the ground pistachios and ground spices. Pour the mixture into the pastry case, smooth the top flat, then bake for 20 minutes.
6. Meanwhile, strain the cherries, reserving any juice in a small bowl. Remove the tart after 20 minutes and arrange the cherries on top. They will sink a little, but not completely. Return to the oven and bake for another 15-20 minutes. Leave the tart to cool and set for 10 minutes, then brush over the reserved syrup to glaze.