In a large bowl stir together granulated sugar, cornstarch, flour, and apple pie spice. Add apples, frozen rhubarb, and frozen raspberries; toss gently to coat. Let stand about 45 minutes or until frozen fruit is partially thawed but still icy.
Meanwhile, preheat oven to 375°F. Prepare Almond Star Crust. On a lightly floured surface roll one pastry ball into a 12-inch circle. Ease pastry circle into a 9-inch pie plate without stretching it. Stir fruit mixture; transfer to pastry-lined pie plate. Trim pastry even with pie plate rim.
Roll remaining pastry ball into a 12-inch circle. Using a 1/2- to 1-inch star-shape cutter, cut out pastry to make 28 to 30 tiny stars; set aside. Using 2- and 3-inch star-shape cutters, cut remaining pastry into stars. Reroll scraps to cut additional stars.
Lightly brush edge of pastry in pie plate with water. Place tiny stars in a single layer on edge of pie. Place remaining stars on top of pie (some filling will show through). If desired, lightly brush cutouts with water and sprinkle with coarse sugar.
Cover edge of pie loosely with foil. Place pie on middle oven rack. Line a baking sheet with foil; place on bottom rack to catch any drips. Bake for 50 minutes. Remove foil from pie. Bake for 25 to 30 minutes more or until pastry is golden and filling is bubbly. Cool on a wire rack.
In a large bowl stir together flour, ground almonds, and salt. Using a pastry blender, cut in shortening and butter until pieces are pea size. If desired, sprinkle with almond extract; toss gently with a fork. Sprinkle 1 tablespoon of the water over part of the flour mixture; toss gently with fork. Push moistened pastry to side of bowl. Repeat moistening flour mixture, using 1 tablespoon of the water at a time, until all of the flour mixture is moistened. Gather flour mixture into a ball, kneading gently until it holds together. Divide pastry in half; form halves into balls.