The following is from another blog I previously contributed to, the now defunct bangkokfood.blogspot.com. I thought I'd reprint a few of the relevant entries.
Thai food is somewhat different from the food I grew up eating and is somewhat different than what most westerners consider "normal." Of course, if you have an idea that normal actually exisits, you should never leave home as a panic attack will likely ensue and nobody will want to be around you when that happens. Of a particularly delicious dessert, a co-worker exclaimed "It isn't really like dessert at all is it?" Of course the phrase :"It isn't really proper (insert food name here) is it?" has been uttered far too many times to count. The point is Thai desserts are a little different. They're served hot, cold, frozen, etc. They're sweet, salty, savory, and or somehwere in between. The idea is that a dessert is often comprised of flavors that mix together making a complex and rich taste. It's actually a lot like a delicious Thai meal eaten family style. You are not meant to eat just one dish by yourself, but order many dishes to share as a group to enjoy the best possible complimentary spread of flavors. Thai food is also known for its complexity and that means they do things that we westerners find crazy at first like putting sugar in their noodles. Desserts are the same on a small scale: provide a range of flavor that is not simply sweet. Got it? They are also often made of ingredients that would be more likely to find themselves on a dinner plate than a dessert bowl in the western hemisphere. Common ingredients include beans, corn, squash, sweet potato, and taro.
Here's a good example. This is tapioca with corn and salty coconut milk. The coconut milk by itslef is quite salty, but mixed in with the tapioca and corn makes the flavor just right. The corn kernels add a bit of crunchy texture.
This is a favorite. It is sweet custard in a pumpkin that is slightly bitter. It is really sweet and rich. It's best to have someone to share it with.
Here's a gorgeous spread of desserts bought without regard to calories.