Preheat the oven to 180°C, fan 160°C, gas 4. Whizz the flour, icing sugar and diced butter in a food processor until the mixture resembles breadcrumbs. Transfer to a large bowl, add the egg yolk mixture and stir with a palette knife. Bring the mixture together with your hands to form a dough, adding an extra teaspoon of chilled water if dry. Roll into a ball, wrap in clingfilm and leave to rest in the fridge for 30 minutes.
On a lightly floured surface, roll out the pastry to the thickness of a £1 coin. Carefully line a 24cm fluted, loose-bottomed tart tin with the pastry, leaving about 1-2cm hanging over the edge. Prick the base with a fork and place in the freezer for 10 minutes to firm up.
Line the pastry with greaseproof paper and baking beans or uncooked rice and bake 'blind' in the oven on a baking tray for 15 minutes. Remove the baking beans or rice and return the pastry to the oven for 10-15 minutes, until golden. When the pastry has cooled, use a small sharp knife to trim the edges.
Meanwhile, make the sponge. Whisk the softened butter and caster sugar together in a bowl until light and fluffy. Beat in 1 egg at a time, with 1 tablespoon ground almonds each time. Stir through the remaining ground almonds and the almond extract.
Spread the jam across the bottom of the pastry case. Pour over the sponge mixture and sprinkle with the flaked almonds. Bake for 45 minutes, until golden. When a skewer is inserted into the centre, it should come out clean. Remove from the tin and leave to cool. Great served with cream.
Cook’s tip: Bakewell tarts traditionally use raspberry jam but you could use any flavour you have in the cupboard – or even lemon curd.