Grease and ovenproof dish with butter. Slice the hot cross buns into 2 cm slices and layer out in the dish.
Add milk, cream, cinnamon and marmalade to a mixing bowl and whisk.
Crack eggs and add to another mixing bowl with caster sugar, then whisk and set saide.
Heat a saucepan over a low to medium heat. Add the contents of your mixing bowl to the saucepan, heat gently, be careful as to not allow the mixture to boil.
Slowly pour the heated milk and cream to the mixing bowl with the eggs and sugar, making sure you whisk constantly while doing so that it does not curdle. Then pour this mixture over the hot cross bun slices in the greased ovenproof dish.
Preheat oven to 160°C
Allow the hot crossed bun slices to rest for 15 minutes, then bake for 35 minutes