All the fun you can have with a bagel.
Marina and I have been watching the Joy of Thinking series from the Teaching Company. In the episode "A Twisted Idea: The Mobius Band," Prof. Starbird explained how to cut open a bagel so that it all stays in one piece. Frankly, we just enjoy hearing Professor Starbird say "mobius."
Hard to explain, but if you were to trace around this bagel, for example, with butter, you would find that it only has one side. It took 2 bagels and 2 donuts before Marina figured out how to cut it. And then figure out how to cut it without having a section break when she pulled it open. I'm so proud.
For those of you interested in making your own Mobius bagel, first you cut straight down from the top, and then as you work your way around the bagel you twist the knife so that it is eventually coming in from the side. Continue twisting as you cut until you are cutting up from the bottom and meet your original incision. Think of it as cutting a spiral. Marina's tip: Always keep your cut centered or thin sections may fall apart when you open it.