From Costco—dense, gluten free little muffins full of seeds and dried fruits, generally available both individually wrapped as well as stacked. (though maybe only the wrapped kind are available for delivery these days?)
Sturdy enough that you could make a pyramid of them at an event, but if you throw a pre-packaged one in your backpack, there’s a fair chance that it will become a little crumbly.
Heating them for a bit in the microwave — which I recommend — also causes some sort of structural integrity issue, so you’ll want a small plate to be sure you get all the crumbs. I usually eat them with a milky black tea (
I have a friend who complains about the chia seeds he finds in his teeth afterward, but I don’t think that is actually a deterrent. 🙃