James wrote:

After having lunch at a Japanese restaurant yesterday, it occurred to me
that tempura sweet potatoes (that I like a lot!) or even squash are quite
sweet and would make good desserts.

Sweet potatoes (especially purple yam) *are* eaten as desserts in Asia. I'm
guessing you could substitute sweet potatoes for the pumpkin in this recipe
and it would turn out fine:

http://www.foodnetwork.com/food/reci..._12908,00.html

Bob