How to Make It
Cover a large baking sheet with parchment paper; coat with cooking spray.
Combine sugar, corn syrup, 1/4 cup water, and salt in a medium, heavy saucepan. Bring to a boil over medium heat until a candy thermometer registers 250°. Add pistachios; cook 15 minutes or until temperature reaches 300°, stirring frequently.
Remove from heat; stir in butter, baking soda, and vanilla. Pour pistachio mixture onto prepared pan, spreading evenly into a 12 x 8-inch rectangle. Cool completely; break into pieces before serving.