My family love that recipe and we make it for Christmas every year. We make 3 times the amount of custard mentioned so it fills the trifle bowl. This is the recipe, I have transcribed it from my Aunties scribbled torn out page of a notebook
Chocolate custard trifle
1 packet strawberry jelly
225gm jam sponge roll
1 punnet strawberries
2 1/2 cups of milk
3 tablespoons custard powder
3 tablespoons cocoa
1/2 cup sugar
300ml cream
1 block chocolate
Cut cake into slices and line a trifle bowl
Cut strawberries in half and layer over the cake around the bowl - leave some for decorating on top
Make jelly and pour over the cake and strawberries
Refrigerate for 30 minutes
Make custard by combining the custard powder, milk, cocoa and sugar
Stir over medium heat until it boils and thickens
Remove from heat and stir in half the cream mixing well
Cool custard slightly and add to the trifle
Refrigerate until cold and the custard is firm
Whip the remaining cream
Grate the chocolate
Decorate the trifle with the whipped cream, chocolate and remaining strawberries