Or if you want to support a small family business instead of a big box store, you might be able to get it from http://ackroydsbakery.com/ but they don't have online ordering. You would have to call.

My grandmother made Christmas pudding with custard sauce when I was a kid. Haven't had it since then. I should probably make a trip to Ackroyds!


Edit: just found their online Christmas store: https://squareup.com/market/ackroyds-christmas-store