Heat the oven to 400 degrees F.

Sprinkle the work surface with 2 tablespoons sugar. Unfold the pastry sheet onto the sugar. Roll the pastry sheet into a 10 x 9-inch rectangle. Cut into 8 (4 1/2x2 1/2-inch) rectangles.

Stir the cornstarch and water in a small bowl until smooth. Heat the berries, lemon zest and remaining sugar in a 2-quart saucepan over medium heat to a boil. Stir in the cornstarch mixture. Cook and stir for 5 minutes or until mixture boils and thickens. Spoon the berry mixture into a 3-quart shallow baking dish. Top the berry mixture with the pastry rectangles, sugar-side up, but not touching.

Bake for 20 minutes or until pastry is golden brown. Let the cobbler cool in the baking dish on a wire rack for 10 minutes. Serve with the ice cream.