How to Make It
Fill a large bowl with ice water and set a metal bowl in it. In a medium saucepan, combine the sugar with 3 tablespoons of water and cook over moderate heat, stirring to dissolve the sugar. Cook undisturbed until a deep-amber caramel forms, about 6 minutes. Remove the saucepan from the heat and add the cream and salt. Stir until the caramel cream is smooth, about 2 minutes. Scrape the cream into the metal bowl in the ice water bath and let cool, then refrigerate the cream until very cold, at least 3 hours or overnight.
In a heatproof measuring cup, microwave the sugar with 1/2 cup of water at high power until the sugar is dissolved, about 2 minutes. Stir in the tangerine juice, lemon juice and salt. Pour the mixture into an 8-by-11-inch baking pan. Freeze for 30 minutes. Stir the granita with a fork. Continue stirring the granita every 30 minutes, until the icy crystals are fluffy, about 3 hours. Cover with plastic wrap.
Spray a sheet of parchment paper with vegetable oil spray. In a small saucepan, combine the sugar with 2 tablespoons of water and cook over moderate heat until the sugar is dissolved. Cook undisturbed until a deep-amber caramel forms, about 6 minutes. Pour the hot caramel onto the parchment paper and let cool completely, about 30 minutes. Break the caramel crunch into small shards.
Using an electric mixer, beat the caramel cream at high speed until firm peaks form. Spoon the cream into glasses. Fluff the granita with a fork and spoon it into the glasses. Garnish with the caramel crunch and serve right away.