One more from the endless list of Thai sweets & desserts: Khanom Thuay, which are small cups of sweet pandanus leaf or coconut jelly, with some thicker coconut custard on top. They're made in little ceramic cups, but then taken out before serving. Be careful though that the white coconut custard can be a bit on the salty side; this is done to balance the sweetness of it all. I personally don't like it when it's too salty..
The pictures here are of a random street vendor, this one near Wat Nantharam off Wua Lai road just South of the city center. I think one of the best in Chiang Mai can probably be found at the Three Kings Monument, near all the little restaurants and vendors. (See http://chanchao.fotopages.com/?entry=70686(this review))
A small serving, often packed in banana leaf goes for a friendly 10 baht..