Cranberry Pear and Chocolate Trifle

6 ripe pears
8 tbsp whisky
100g / 3 1/2 oz caster sugar, plus 4 tbsp
450g / 1 lb cranberries, defrosted if frozen
250g / 9 oz ready-made chocolate sponge, cut into 1 cm / 1/2 inch slices
50g / 2 oz good-quality plain chocolate, chopped, to decorate

For the white chocolate custard:
150g / 5 oz good-quality white chocolate, chopped
400ml / 14 fl oz fresh custard
300ml / 1/2 pint double cream

For the pear crisps:
2 ripe pears
100g / 3 1/2 oz sugar

First prepare the pear crisps: preheat the oven to 130ºC / fan oven 110ºC / gas mark 1/2 and line a baking sheet with baking paper. Without peeling or coring them, slice the 2 pears very thinly from top to bottom. In a frying pan, dissolve the sugar in 100ml / 3 1/2 fl oz water over a medium heat. Bring to the boil, then simmer for 2-3 minutes. Remove from the heat, add the pear slices and leave for 2 minutes, then removewith a spatula and place on a baking sheet. Place in the oven for 1 1/2 hours until just golden, then cool on a wire rack.

Meanwhile, peel, core and quarter the remaining 6 pears. Heat 600ml / 1 pint water with a quarter of the whisky and the 100g / 3 1/2oz sugar in a large pan, stirring, until the sugar has dissolved. Add the pears and simmer gently for 7-8 minutes until just tender. Drain and set aside to cool.

In a pan set over a gentle heat, cook the cranberries and the remaining 4 tablespoons of caster sugar until the berries just start to soften. Drain a spoonful on kitchen paper and reserve for decoration. Set the rest aside to cool. 4 Layer half the sponge in the bottom of a glass serving dish. Sprinkle with half the remaining whisky. Arrange half the pear quarters on top and cover with half the cranberries. Repeat the layers.

Make the white chocolate custard: melt the chocolate in a heatproof bowl set over a pan of simmering water (not touching the water), then leave to cool. Pour the custard into a large bowl and stir in the melted chocolate. Lightly whip the cream and fold into mixture. Pour over the trifle and chill until set.

To decorate, stand the pear crisps in the top of the trifle, and sprinkle over the reserved cranberries and chopped plain chocolate, serve the Cranberry Pear And Chocolate Trifle immediately.