In a small saucepan, combine sugar and cornstarch. Gradually stir in water until smooth. Stir in blueberries and lemon juice. Bring to a boil over medium-high heat. Reduce heat; simmer, uncovered, for 5 minutes or until slightly thickened, stirring occasionally. Cover and refrigerate until chilled., In a large bowl, combine the cracker crumbs, sugar and cinnamon. Stir in butter. Pat into an ungreased 15x10-in. baking pan. Bake at 350° until lightly browned, 10-15 minutes. Cool completely on a wire rack., Meanwhile, in a large bowl, whisk the ice cream ingredients. Fill ice cream freezer cylinder two-thirds full; freeze according to manufacturer's directions. Refrigerate remaining mixture until ready to freeze. Whisk before adding to ice cream freezer (mixture will have some lumps)., Crumble the graham cracker mixture. In a large container, layer the ice cream, graham cracker mixture and blueberry sauce 3 times; swirl. Freeze.