3/4 cup hot water
3/4 cup sugar
2 tablespoons fresh lemon juice
3 cups fresh raspberries, plus more for garnish
3/4 cup cold champagne
Mint sprigs to garnish
Mix the hot water, sugar and lemon juice until the sugar is dissolved. Cool completely. Purée raspberries in a food processor or blender, until smooth. Strain purée through a fine strainer. Mix sugar syrup, raspberry purée and champagne.
Pour mixture into 13 x 9 x 2-inch Pyrex baking dish (or other, nonreactive baking dish). Freeze until icy around edges, about 25 to 30 minutes. Using a fork, stir icy portions into middle of pan. Freeze until mixture is frozen, stirring edges into center every 20 to 30 minutes, about 1 1/2-hours. Using a fork, scrape granita into flaky crystals. Cover tightly and freeze. This may be done a day ahead and kept frozen. Scrape granita with a fork and into small bowls or small glasses. Garnish with mint and serve.