Maple syrup—and, to a lesser extent, honey and agave—may be the boutique sweetener in the U.S., but it's all about palm sugar in Southeast Asia. Particularly in Malaysia and Indonesia, you'll find some of the best tasting sugar around, made with the care and attention granted to fine wine. Rather than a single product, this is a whole class of sugars; different regions use different palms, extraction methods, and local terroir to create distinct and unique products.
In all these cases, sap is harvested from palm trees (the trunks for palm sugar, the flower blossoms for coconut sugar), boiled down, and poured into molds to harden. The resulting lumps can be shaved, cut into chunks, or made into syrup for use. Most palm sugar, at least of what you'll find in the U.S., is cut with cane sugar; even small batch artisans are having trouble using 100 percent arenga (a catch-all word for "palm") these days. While there are subtle differences in flavor between coconut and palm sugar, styles of manufacture can have just as much, if not more, of an impact.
Most of the palm sugar you'll find in Asian groceries (or on the web) looks like the photo up top: formed into discs, blocks, or as a solid mass in plastic jars (usually with a layer of wax on top). It's a fairly processed form of palm sugar, plenty diluted by cane, but it bears the fresh, fruity nuttiness of green coconut and the warm vibes of sweetened condensed milk. It tastes great with those ingredients, but I also use it as a serious upgrade to Thai curries, chai (with plenty of cardamom and clove), and pungent vegetable stir fries.
That gentle warmth jives well with desserts, particularly with egg-rich. Take a hint from my ice cream buddy Ethan Frisch and put some leftover massaman curry paste to work in palm sugar-sweetened desserts as well, either in sorbet or as a crème brûlée (ridiculously good, that).
Palm sugar tastes fresh enough to play well with citrus, particularly kumquat and pomelo, but also with lime. Though it can't be used interchangeably with brown sugar (it's less moist and the acidity can vary), it's worth experimenting in citrus-scented cookies. Or for a more exotic spin on lemony poundcake, try a palm sugar glaze in lieu of the powdered stuff. Palm sugar also takes well to lighter nuts like almonds and macadamias. Your dessert possibilities abound.
I'd be remiss in discussing palm sugar if I left out gula jawa and its close relatives—the darker, less processed form of palm sugar. First encounters are reminiscent of someone's first bite of caramel when all they've had is table sugar. There are powerful notes of roasted coffee, smoke, and caramel, with the weighty satisfaction of fudge offset by an addictive bitterness and a verdant twang. Look in Indonesian- and Thai-friendly groceries for it, where it will be sold in cylinders. You can also find it online at Gilt Taste.
This is sugar best treated like a fine balsamic vinegar. Use it sparingly as an accent on breakfast fare like oatmeal, or add a tiny bit in a saucy, vinegar-rich (especially black vinegar) stir fry. It can accompany strawberries, peaches, or mangoes with nothing more than frothy cream to make a fruit-based dessert that doesn't feel like it's missing something. It's the only sugar I know of that should be used sparingly not because it'll oversweeten a dish, but because it'll be too pungent.
My favorite use for this sugar powerhouse is cendol, the Indonesian dessert of pandan-scented bean noodles, shaved ice, coconut and/or sweetened condensed milk, and dark palm sugar syrup. It's a delightfully slurpy, chewy, and crunchy interplay of light-yet-rich tropical flavors, largely in thanks to butterscotch-like palm sugar. But since it's a pain to make at home—you must make your pandan extract, form your noodles spaetzle-style, boil and cool your syrup, shave your ice, and then assemble—I take the easy way out and enjoy a simple dish of shaved ice with coconut milk and palm sugar syrup. Not as complex, mind you, but perfect on a summer evening.
A few commenters asked how to actually use palm sugar. For applications requiring moist, brown sugar-like grains, I grate the sugar on a microplane. But for most uses, like sweetening drinks or melting into a syrup, I hack the sugar apart with a $15 Chinese meat cleaver, then mince it into small chunks. That cleaver, by the way, also gets pulled out every time I have to cut squash, chop chocolate, or mince garlic.
Palm sugar is the best case I know for why sugar is more than just a sweetener. Do you have any favorite uses for it?
Disclosure: gula jawa sample pictured here provided for review.