Roll out the pastry thinly and line a deep 18 cm (7 in) pie plate.

Spread the bottom of the pastry with the jam.

Cream the fat and sugar with the lemon rind until pale and fluffy.

Add the egg a little at a time and beat after each addition.

Mix together the cake crumbs and ground almonds, fold half into the mixture with a tablespoon, then fold in the rest, with a little lemon juice if necessary to give a dropping consistency.

Put the mixture into the pastry case and smooth the surface with a knife.

Bake in the oven at 220°C (425 F) mark 7 for about 15 minutes, until the tart begins to brown;

reduce the temperature to 180°C (350°F) mark 4 and cook for a further 20-30 minutes until the filling is firm to the touch,

Serve hot or cold, with cream or custard.