Preheat the oven to 350 degrees F (175 degrees C). Line a baking sheet with parchment paper.
Add walnuts to a heat-resistant bowl.
Melt butter in a nonstick skillet over medium heat. Mix in honey and cayenne pepper and pour mixture over walnuts in the bowl. Mix well. Spread coated walnuts onto the prepared baking sheet and quickly separate nuts using a spatula or fork.
Bake in the preheated oven for 10 minutes. Stir and continue baking until golden brown, 5 to 10 minutes more.
