Preheat your oven to 170°C and line or butter an ovenproof dish.
Cut the buns in half and spread butter on both sides. Arrange the bottom halves in the buttered dish.
Whisk together the remaining ingredients and slowly pour half of the mixture over the bottom halves, making sure to cover everything.
Place the top buns on the bottom halves. Add a teaspoon of our Priory Farm Orange and Whiskey Marmalade to glaze each bun.
Pour the remaining mixture over the buns. Ideally, let the buns soak in the mixture for 30mins.
Bake for around 45 minutes or until the buns are puffy and rich dark brown. Serve with your choice of custard or ice cream.