Preheat oven to 400°F. In a medium bowl, combine nuts and pineapple, tossing to combine. Spread in a single layer on a rimmed baking sheet. Bake 8-12 minutes or until golden-brown, stirring once. In a medium bowl, combine rosemary, cayenne, sugar and salt. Drizzle with melted butter; stir well. Add warm nuts to bowl; toss to coat. Spread mixture in a single layer on baking sheet. Bake 3-5 minutes or until sugar coating is melted. Serve warm or room temperature.