Cheat's trifle

Instructions

1. Put the blackberries and sweetener in a small pan with 4 tbsp water and bring to a simmer. Cook for 5 minutes, then crush slightly. Let cool.
2. Meanwhile, dissolve the jelly mix in 280ml boiling water then stir in 280ml cold water. Set aside to cool.
3. Pour the jelly into four glasses and chill until almost set. Scatter over the biscuit pieces and spoon over the blackberries, then chill until completely set. Finish with the custard and cream. Serve decorated with sprinkles.