For the pastry, mix flour and salt and rub in the butter.
Add 1 tbsp cold water and bind to a dough, roll out pastry on a floured surface and line the tartlet tins with it. Put a tsp of apricot jam on the base of each pastry shell.
To make filling, beat butter and sugar till creamy, add in egg and almond essence, fold in flour and ground almonds. Mix well and spoon it in the pastry cases.
Arrange a few flaked almonds on top. Bake at 190 degrees C for 15-20 minutes or until golden. Meanwhile, heat apricot jam with a tbsp of water in a pan and sieve it to remove any fruity bits, brush over hot tarts and let tarts cool and serve.