Line a baking sheet with parchment paper. Set aside. In large heavy saucepan, combine sugar, corn syrup and 1/2 cup (125 mL) water over medium-low heat, stirring until sugar is melted, about 5 min.
Increase heat to medium and bring mixture to a boil. Cook, without stirring, until a candy thermometer inserted into syrup reaches soft ball stage, 235°F (118°C), 15 to 18 min. Occasionally brush inside of saucepan just above syrup with heatproof pastry brush dipped in cold water (this prevents hard bits of candy from forming around edge).
Stir in pine nuts and butter. Continue to heat and cook, stirring constantly, until mixture reaches 300 °F (149°C), the hard crack stage. Mix in baking soda, orange zest, rosemary and salt. (Mixture will bubble up.) Immediately pour mixture onto prepared baking sheet and use a heatproof spatula to spread into 1/4-in. (5-mm) thick layer. Cool completely.
Break candy into pieces. Layer between pieces of waxed paper in airtight container for up to 2 weeks.
If you don't have a candy thermometer, test candy doneness by dropping a teaspoonful of the hot syrup into a cup of cold water. At the soft ball stage, the syrup will form a malleable ball. At the hard crack stage, the syrup will form hard brittle threads.