Preheat the oven to 180C. You will be using a medium sized baking dish for this pudding. (we used a 28x22cm rectangular baking dish).
Slice each hot cross bun into 1cm thick slices, about 3 or 4 slices per bun. Arrange the slices in the baking dish, so that they are overlapping and on an angle, until the dish is full.
In a medium bowl, whisk together the eggs, caster sugar, Tatua cooking cream, milk, vanilla and orange zest, and pour over the hot cross buns. Gently press the buns down so that every part is soaked in the custard mixture.
Sprinkle the sugar over the top of the pudding, and bake for 25-30 minutes until the top is golden and crunchy, and the custard has just set (you want it thickened, not runny).
Allow the pudding to stand for about 15 minutes before serving, and enjoy with fresh cream or ice cream.