Line a baking sheet with parchment paper; set aside.
In a medium saucepan, combine sugar, corn syrup, vanilla extract, and salt. Bring to a boil over medium-high heat. Cook for about 10 minutes, stirring occasionally, until temperature registers 340° on an instant-read thermometer or mixture is amber colored.
Remove from heat. Quickly whisk in baking soda. Caution: Hot mixture will bubble vigorously. Once baking soda is incorporated, discontinue stirring. Pour mixture onto prepared baking sheet. (Do not attempt to spread.) Let candy cool until hardened. Break into pieces. Candy can be stored, at room temperature, in an airtight container for up to 1 week.
Recipe by Victoria at https://victoriamag.com/pistachio-cardamom-ice-cream-sundae/