Line a rimmed baking sheet with parchment paper; spray lightly with cooking spray and set aside. In a medium saucepan, stir together sugar, corn syrup, water and curry powder; bring to a boil over high heat, stirring occasionally, just until sugar dissolves. Continue to cook until mixture reaches 290° (5-7 min.). Use a silicone spatula to mix in cashews, butter and salt. Continue to cook, stirring often, until mixture reaches 300°. Sprinkle baking soda over mixture; stir quickly to combine. As soon as soda is mixed in, pour mixture onto the prepared baking sheet; spread hot mixture as thinly as possible. Cool completely. Break into pieces and store in an airtight container for up to 1 week.