Blackberry Granita

Directions

1. 1.

   Purée blackberries, sugar, crème de cassis, if using, lemon juice, salt, and 1 cup water in a blender until smooth. Strain purée through a fine-mesh sieve into a 13x9x2" baking pan, pressing on solids.

2. 2.

   Freeze mixture until edges begin to set, about 30 minutes. Using a fork, scrape to break up frozen portions. Freeze, scraping and breaking up mixture every 20-30 minutes, until mixture resembles fluffy shaved ice, 2-4 hours.

3. 3.

   DO AHEAD: Granita can be made 3 days ahead. Cover with plastic wrap and keep frozen. Scrape before serving.

4. 4.

   Just before serving, whisk mascarpone, cream, sugar, lemon juice, vanilla, and 1/2 teaspoon lemon zest in a medium bowl until soft peaks form.

5. 5.

   Serve granita topped with lemon cream, halved blackberries, and more lemon zest.