Dissolve 1 teaspoon of the gelatine in the water in a bowl over a saucepan of gently simmering water.

Poach the cooking apples with the lemon rind and juice and a few tablespoons of water until tender. Add sweetener to taste and beat in the egg yolk. Stir in the gelatine.

Bake the muesli in the oven for 8 minutes. Mix with the low-fat spread while still hot. Spread the muesli over the base of a loose-bottomed 18 cm/7 inch cake tin. Chill for 30 minutes.

Poach the dessert apple slices gently in the apple juice for about 3 minutes; remove carefully and drain on absorbent kitchen paper.

Dissolve the remaining gelatine in 2 tablespoons of the apple juice in a bowl over a saucepan of gently simmering water. Stir in the remaining apple juice.

Spread the apple puree over the muesli base; arrange the apple slices on top. Spoon over the apple juice glaze and chill for 4 hours.