Soak sultanas overnight in the Calvados. Melt butter and sugar in a small saucepan, add biscuit crumbs and nuts and stir until well mixed.

Press evenly over bottom of a greased, loose bottomed 7 inch (18 cm) cake tin, chill.

Soften the cheese in a large mixing bowl. Beat in egg yolks, 2 oz (50 g) of the sugar, lemon rind, flour, sultanas and Calvados liquid.

Whisk egg whites until stiff and whisk in remaining sugar. Fold lightly into cheese mixture and turn into prepared tin, smoothing surface. Arrange slices of apple in concentric circles on top.

Bake in a moderately slow oven Mark 3 (160°C) 325°F for 1 1/2 to 1 3/4 hours until firm but still spongy to touch. Turn off oven,

leave cheesecake to cool with door open for 1 hour. Place jam in a saucepan with 2 tbsp water and bring to the boil. Sieve, then brush glaze over top of cheesecake. Chill for 2 to 3 hours. Remove from tin.