Begin by making the caramel sauce, to do this place the sugar along with the water into a saucepan and heat on a medium heat until the sugar has dissolved.
Then increase the temperature and cook bubbling for 5 minutes until the mixture has turned to rich caramel colour. Remove from the heat and then stir in the cream, butter and salt, when fully incorporated leave to cool.
Next make the chocolate custard. First, chop the chocolate into chunks and place into a heatproof bowl.
Bring about an inch of water to a simmer in a saucepan. Place the heatproof bowl in the mouth of the pot, making sure the water doesn’t touch the bottom of the bowl. Stir occasionally until melted thoroughly.
Heat the custard in a pan and stir the melted chocolate through the custard until combined and leave in the fridge to cool. Finally whip the cream to soft peaks and keep in the fridge until needed.
To build the trifle slice the hot cross buns in half and lightly grill them. Keep the top halves with the crosses to one side then cut the 6 bases into quarters and fill the base of the trifle dish with them.
Pour over half of the amaretto (optional), and then drizzle half of the caramel sauce on top of the hot cross buns. Next add half of the chocolate custard on top followed by a half of the whipped cream.
Then arrange the 6 remaining halves of hot cross buns against the edges of the trifle dish making sure that the cross side is visible.
Drizzle the remaining amaretto over the buns (optional) and then drizzle most of the caramel sauce over the hot cross buns, hold back a couple of tablespoons of sauce for the topping.
Pour the rest of chocolate custard into the centre of the buns and then top with the remaining cream.
Decorate the trifle with grated chocolate and drizzle over the caramel sauce.
Cut 1 hot cross bun into 3 small square pieces and add to the centre of the cream.