How to Make It
Heat oven to 375° F. Melt the butter in a medium skillet over medium heat. Stir in the sugar, cayenne pepper, and ½ teaspoon salt. Add the pecans and toss to coat.
Transfer the pecans to a rimmed baking sheet and arrange in a single layer. Bake, stirring occasionally, until toasted, 10 to 12 minutes.
Add the rosemary and toss to combine. Serve warm or at room temperature.