Preheat oven to 350 degrees F (175 degrees C). Line two baking sheets with aluminum foil and lightly coat with cooking spray.

Combine the walnut halves, almonds, and cashews in a large bowl. Add salt, black pepper, and cayenne pepper; toss to coat.

Heat honey, water, and butter in a small saucepan over medium heat until the butter is melted. Cook for 1 minute and remove from heat. Slowly pour butter mixture over the bowl of nuts and stir to coat.

Transfer nuts to the prepared baking sheets and spread them into a single layer.

Bake nuts in the preheated oven for 15 minutes. Stir nuts until the warm syrup coats every nut. Spread into a single layer and return to the oven, and bake until nuts are sticky and roasted for about 10 minutes.