Combine the fruit, sugar and liqueur in a saucepan and gently cook for 5-8 minutes, or until the liquid has reduced a little. Remove from the heat.
Lightly butter a 1 litre/1¾ pint pudding basin.
Line the bowl carefully with most of the bread using small pieces to cover any holes in the side or bottom, then pour in nearly all of fruit (leave a little cupful aside for garnish). Cover with a lid of bread and then use a dish or lid to press down firmly (you could use two dishes to get some weight). Set aside in the fridge overnight.
Melt the white chocolate gently in a bain marie or a bowl suspended over a pan of gently simmering water (do not let the bottom of the bowl touch the water). Allow to cool slightly and then stir in the cream. Add the mascarpone and mix in the icing sugar.
Turn the pudding onto a dish, drizzle with the leftover fruit and serve with the white chocolate cream.