Sieve together the flour and 120 g (4 oz) of the sugar into a bowl. Rub in the butter, until the mixture resembles fine breadcrumbs.

Make a well in the centre of the flour mixture and drop in the egg. Gradually incorporate the flour into the egg using a knife or, as the mixture becomes firmer, your fingers. Continue kneading the mixture together, until it forms a smooth dough.

Wrap the dough in greaseproof paper and chill for at least 30 minutes in the refrigerator.

Roll out the pastry and use it to line a 20cm/8 inch greased pie dish.

Layer the apple slices and the ground hazelnuts in the pastry case. Sprinkle over the cinnamon, remaining sugar, lemon juice and apricot brandy, if using.

Put the apricot jam into a small saucepan and heat through gently until it has melted. Pour the melted jam over the layers of apple and hazelnut.

Sprinkle with the chopped hazelnuts and bake in a preheated oven, 220°C/425°F/Gas Mark 7, for 35-40 minutes, or until the fruit is soft and the tart is golden brown.