Bring 1/4 cup sugar and 1 tablespoon each light corn syrup and water to a simmer in a saucepan over medium heat; swirl (don't stir) until dark amber, 8 minutes. Remove from the heat; whisk in 1/2 cup heavy cream. Stir in 1/2 cup chopped cashews, 1 tablespoon butter, 1/4 teaspoon vanilla and a pinch of salt. Sever over ice cream.
Photograph by Con Poulos