I've done some reading on bumbleberry--and while it may not be a Canadian term, it certainly is embraced in many kitchens across my fair land.
Add "grunt" -- both as in a Nova Scotian blueberry grunt and another bit of culinary onomatopoeia referring to the sound of the fruit erupting through biscuit dough -- and I think we've got a dish that sounds as good as it tastes.
Bumbleberries, of course, don't exist. The term refers to a mixture of berries, of no particular ratio. Sometimes it includes apples (as this one does), sometimes rhubarb. I mostly have bumbleberry pies and tarts, to use up last bits of berries or to make up enough filling for a pie.
Grunts are one of my favourite quick puddings. Unlike many where you simmer fruit on the hob, this one is entirely done in the oven. I've outlined how to make steamed dumplings below, but if you want more of crispier top, don't cover the dish with foil after you've dolloped the dough over the fruit.
I do recommend serving this shortly after making it. Otherwise, the dumplings could absorb the fruit juices, and you'd be left barren of those that gorgeous claret-coloured sauce.
Place a spoonful or two of dumplings in a bowl and spoon the fruit mixture and its juices over top. If you wish, serve with Chantilly cream, custard or ice cream.