Step 1

Preheat oven to 375°F. Toss together fruit, 1 1/2 cups granulated sugar, 1/3 cup all-purpose flour, vinegar, lemon zest and juice, and 3/4 teaspoon salt in a large bowl. Transfer fruit mixture to a 3-quart baking dish (such as a 13- x 9-inch dish), and spread in an even layer. Set aside.

Step 2

Whisk together mascarpone, butter, 1/4 cup cream, and vanilla bean paste in a medium bowl until mostly smooth; set aside. Whisk together semolina flour, baking powder, remaining 1 cup all-purpose flour, remaining 1/4 cup granulated sugar, and remaining 3/4 teaspoon salt in a large bowl. Add mascarpone mixture to flour mixture; stir with a fork until a shaggy dough forms.

Step 3

Using a 2 1/4-inch scoop, divide dough into 9 mounds (about 1/4 cup each), and arrange on top of fruit filling. Brush dough mounds with remaining 2 tablespoons cream; sprinkle with turbinado sugar.

Step 4

Bake in preheated oven until biscuits are golden brown and cobbler is bubbly and thickened in center, 1 hour to 1 hour and 10 minutes. Let cool on a wire rack 30 minutes. Serve warm with vanilla ice cream.