I nearly jumped when first spying these galls! I mean wow! Some folks liken them to toasted marshmallows and I can see the resemblance. Googling "fuzzy white gall" was the ticket to this ID.
The Wood Sower Gall, home to a group of developing Cynipid Wasps, Callirhytis seminator, is found on White Oak. This single tree, about eight feet high, held something like six of these galls. One branch had a double, two in a row, just the way I used to double up marshmallows on a stick over the fire.
Of course, I had to give one a squeeze. Although seemingly soft and fuzzy, they are really quite firm, not at all like marshmallows. No, I didn't taste them. :-)