Whisk together all ingredients except the cashews and zest until combined. Toss in the cashews and stir them around until they're evenly coated.
Spread the cashews on a baking sheet in one layer. Bake 20-25 minutes, stirring after 10 minutes, until golden brown and fragrant. Cool on a rack - they will crisp up after about 10 minutes. Grate orange zest over the cashews while still warm.