For the sorbet: Combine the tangerine juice, sugar and Campari if using in a medium saucepan. Bring to a simmer, stirring over low heat until the sugar is dissolved. Chill the mixture in the refrigerator for about 20 minutes then process the sorbet in an ice cream maker according to the manufacturer's instructions. Transfer to a bowl, cover tightly and freeze until firm, at least 2 hours and up to 3 days.
For the pistachios: Place a rack in the middle of the oven and preheat the oven to 350 degrees F. Line a baking sheet with parchment paper.
Stir the sugar, 1 tablespoon water and the salt together in a medium bowl. Add the pistachios and stir to coat. Spread the pistachios on the prepared baking sheet and bake until the nuts are golden and crisp, about 8 minutes. Allow the nuts to cool, then coarsely chop and set aside.
For the vanilla cream: Place the cream in a small bowl. Use a paring knife to scrape the beans from the pod into the cream. Add the empty pod and refrigerate until ready to use.
To serve, pour 2 tablespoons of the vanilla cream into a martini glass. Add a scoop of sorbet and garnish with pistachios.