Heat sugar in a 4-qt. saucepan over medium-high heat, and cook, stirring with a wooden spoon, until it becomes a liquid, golden caramel.
Add pine nuts and then butter, and stir until butter is fully absorbed by caramel.
Stir in half each the rosemary and salt, and then pour onto a parchment paper-lined baking sheet, spreading to create an even layer; sprinkle with remaining rosemary and salt while warm.
Let cool completely and then break into bite-size pieces. Store in an airtight container between sheets of wax paper.