In a small saucepan, combine sugar and cornstarch. Gradually stir in water until smooth. Stir in blueberries and lemon juice. Bring to a boil. 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 15-in. x 10-in. x 1-in. baking pan. Bake at 350° for 10-15 minutes or until lightly browned. 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 three times; swirl. Freeze. Yield: 2 quarts.