Mix salt, spices, and 1 tsp water together in a bowl.
Add cashews and toss to coat. If the spices are clumping together, add more water 1 tsp at a time.
Spread the cashews on a baking pan, taking care not to crowd the pan (see Note 2).
Roast in the oven at 350 °F for 10–12 minutes, shaking halfway to turn (see Note 3).
Notes
A quarter sheet pan is just the right size for one batch of this recipe, fitting all the cashews on one pan without overcrowding them. You can use pans of other sizes, but be aware that the closer together your cashews are, they longer they will take to cook. And vice versa, the further apart they are spaced, the quicker they will burn. So it's especially important to check on the cashews frequently if you're using a different-sized pan.
I recommend lining your sheet pan with parchment paper to prevent sticking.
Be careful to check the cashews frequently towards the end of the baking time. I find that anything less than 350 °F and 10 minutes leaves a lingering raw taste, but anything past 12 minutes starts to taste burnt. And this really depends on your oven as well. You may want to start checking on them at 8 minutes to make sure you don't over-brown them, especially if your oven temperature is unreliable. (I used an oven thermometer to double-check that it was 350 °F.)