What to do with crumbled muffins? I made some muffins that apparently didn't have enough liquid to stick together (perhaps substituting Greek yogurt for sour cream was not such a good idea, as that, butter, and an egg contributed the only liquid).  So the muffins crumbled completely on leaving the greased tin.  Are there any culinary uses for them, or am I stuck trying to eat the big chunks and throw the rest out?  They are so crumbly that packing them to the office for breakfast like I usually do won't work.

The specific ones I made are cinnamon coffee cake flavored, but I'd be curious about the general case.
I would make "cake balls" out of them.  Maybe make this Apple Butter Frosting, combine with the crumbles and form balls out of the combo and then freeze or refrigerate them.  I think these would be best served "uncoated" so maybe a quick cream cheese icing drizzle across the tops.  Serve as a dessert and enjoy.