Vlad Taltos series - Steven Brust
"Kragar, shut up and let me drink my klava. Then you can be funny. If you try to be funny before I've had my klava, I will probably have to kill you, and then I'll be sad." - Dragon
In Dragaera, you have options. You can get run of the mill coffee, but you can also follow Vlad's example and drink klava. The delectable-sounding klava starts with coffee. You put coffee through a filter of eggshells, woodchips, and vanilla beans. Reheat to almost boiling and then pour through a cloth to remove oils. It's supposed to be less bitter than coffee, but it sounds like an awful lot of work. Not that we don't go to that kind of trouble in the real world.
Dragonriders of Pern - Anne McCaffrey
"Could I have some klah? I know I'm not making much sense, and I'm not really awake yet. But I'm not mad or still sick and this is rather complicated." - Dragonflight
McCaffrey's put a spin on coffee too. Klah is made from bark instead of beans though. The bark is infused with chocolate, coffee, and cinnamon. It's served hot in steaming mugfuls, as beverages in fantasy novels usually are. You can find a fan recipe for klah here.
Wheel of Time series - Robert Jordan
Since "K" apparently provides the right phonetic sound, you can get your caffeine fix in Randland under the name of kaf. It's primarily a Seanchan drink. The dark and bitter drink is brewed from beans, and it sounds very much like espresso. It's served in small cups without handles. It's not to everyone's taste though; the Westlanders find it way too strong and prefer tea.
Continuing with coffee equivalents starting with "K" from books I haven't read:
Chronicles of Warlands - Elizabeth Vaughan - kavage
Lightbringer series - Brent Weeks - kopi
Dragonlance - Margaret Weis and Tracy Hickman - kefre
The Hobbit - J.R.R. Tolkien
"Some called for ale, and some for porter, and one for coffee, and all of them for cakes; so the hobbit was kept very busy for a while. A big jug of coffee had just been set in the hearth, the seedcakes were gone, and the dwarves were starting on a round of scones..."
And yes, I had to dig - but there is even coffee in Middle Earth. It was the drink of choice for a dwarf. Which is somehow fitting.