Citrus and Mascarpone Parfait with Grapefruit and Prosecco Granita

Name: Citrus and Mascarpone Parfait with Grapefruit and Prosecco Granita
Ingredients: 1 stick (8 tablespoons) cold unsalted butter, cut into pea-size pieces; 3/4 cup all-purpose flour; Heaping 1/4 cup granulated sugar; 1 egg yolk; 1 lemon, zested; Pinch salt; Ice water, a few splashes; Turbinado sugar, for dusting; 1 cup mascarpone; 1/4 cup granulated sugar; 2 Meyer lemons, zested and juiced; 2 cups ruby red grapefruit juice; 1 cup prosecco; 2 satsuma oranges, segmented and halved; 2 navel oranges, segmented and halved; 2 ruby red grapefruits, segmented and halved; 4 fresh mint leaves, chiffonaded