Slice Swiss roll and place in base of trifle dish.
Heat custard and 1/2 block of milk chocolate, broken into pieces in a pan, till melted, then pour over the Swiss roll; leave to chill.
For the fudge sauce, place dark chocolate, butter, caster sugar, golden syrup, and 2 teaspoons of water in a pan and heat. Bring to the boil (necessary to thoroughly melt sugar) then lower heat for 5 minutes, stir regularly. Take off heat and stir in vanilla extract. Then pour over the custard mix; leave to chill.
Wash and slice strawberries and pour Kirsh over them. Then arrange them on top of the trifle. Save 3 strawberries for top of trifle.
Whisk up cream to thick consistency, spread over strawberries, place last three strawberries in the middle and sprinkle with chocolate sprinkles.