Strange Snack

From July 2011 issue of Country Extra, submitted by U Hoffer of MN:

Quite often my neighbor brings me a cookie or some other treat, which I much appreciate.

One day she came over with something wrapped in a napkin. I thanked her, then peeked inside and saw what looked like some kind of cookie. It was partly squashed from when she wrapped it, but it looked tasty enough, covered with what appeared to be toasted coconut.

I said, "Now tell me what it is so I can eat it."

She looked surprised, then said, "It's a begonia bulb."