Classic Sour Cherry Pie with Lattice Crust

INGREDIENTS

• 1/2 teaspoon vanilla extract
• 3 tablespoons cornstarch
• 5 tablespoons (or more) ice water
• 1 cup (2 sticks) chilled unsalted butter, cut into 1/2-inch cubes
• Vanilla ice cream
• 1/4 teaspoon salt
• 1 tablespoon sugar
• 3/4 teaspoon salt
• 2 tablespoons (1/4 stick) unsalted butter, cut into 1/2-inch cubes
• 1 teaspoon fresh lemon juice (if using sour cherries) or 3 tablespoons fresh lemon juice (if using dark sweet cherries)
• 1 tablespoon (about) milk
• 5 cups whole pitted sour cherries or dark sweet cherries (about 2 pounds whole unpitted cherries)
• 1 cup plus 1 tablespoon sugar
• 2 1/2 cups unbleached all purpose flour