Mix the defrosted berries with ½ teaspoon of the mixed spice and the clementine zest.
Place half of the amaretti biscuits in the bottom of a 2 litre glass trifle bowl (about 20cm in diameter) and top with half of the berry mix.
Whip the cream until it forms medium peaks and then carefully fold in the vanilla custard, ensuring all lumps are removed.
Spoon half of this cream mixture on to the first layer of berries then top with the remaining biscuits and then another layer of the berries and the cream.
Place in the fridge, covered, for a couple of hours. When ready to serve, sprinkle with the toasted almonds and remaining mixed spice.
Cook's tip: If clementines are not in season, you can use Sainsbury's sweet and juicy easy peelers instead.