Got this recipe in a Cook's Illustrated a while ago and have been waiting for an occassion to try it out. I was going through the freezer recently and noticed that I had somehow accumulated a glut of frozen blueberries. Also, was going to a Hanukkah party, mentioned this recipe to the host, and he replied that he LOVED blueberries, so there you go. A buckle is basically fruit with just enough cake batter to hold it together. This batter turned out pretty thick and I had a hard time getting the blueberries evenly distributed, but no one complained.