Khanom piak pun (Thai: ขนมเปียกปูน Thai pronunciation: [khànǒm piàk pūːn]; literally "limewater-dampened sweets") is a type of Thai dessert. It is similar in texture to khanom chan, despite being different in appearance. Khanom chan can be peeled into layers, while khanom piak pun is solid throughout.
It is made with rice flour, palm sugar and precipitated limewater (น้ำปูนใส; RTGS: nam pun sai; Thai pronunciation: [náːm pūːn sǎj]). The word ปูน (lime) gives sweet its name. The mixture is often thickened using arrowroot or tapioca starch. As a colouring, charred coconut coir (fibre from outer husk) or crushed pandan leaves may be added. The mixture is then heated on the brass pan before allowed to set on the tray. Grated coconut may be sprinkled as desired.