Heat oven to 350°F. Line 8-inch square pan with foil. In medium bowl, mix flour, granulated sugar and cocoa. Using pastry blender or fork, cut in butter until mixture looks like coarse crumbs. Stir in ice water to form crumbly mixture. Press mixture in foil-lined pan. Bake 12 to 15 minutes or until set. Cool 10 minutes on cooling rack.