Combine 1/3 cup granulated sugar and cornstarch in small saucepan. Slowly add reserved 3/4 cup peach syrup. Stir well. Add vanilla. Cook over low heat, stirring constantly, until thickened. Set aside.

For crumb topping, combine 1/2 cup flour, brown sugar, oats, butter and cinnamon in small bowl; stir until mixture forms coarse crumbs. Set aside.

Preheat oven to 350°F. Combine remaining 1-1/2 cups flour, remaining 1 tablespoon granulated sugar and salt in small bowl. Cut in shortening with pastry blender or 2 knives until mixture forms pea-sized pieces. Sprinkle water, 1 tablespoon at a time, over flour mixture. Toss lightly with fork until mixture holds together. Press together to form ball.

Roll dough into 10-inch square, 1/8 inch thick. Fold dough in half, then in half again. Carefully place folded dough in center of 8-inch square baking dish. Unfold and press onto bottom and about 1 inch up sides of dish. Arrange peaches over crust. Pour reserved peach sauce over peaches. Sprinkle with reserved crumb topping.

Bake 45 minutes. Serve warm or at room temperature with whipped cream.