"I remember my mother baking this when I was young. She kept my dad guessing for awhile on this one. A good stand-in for the real thing. May use lemon juice instead of cider vinegar."
2Arrange crackers in pastry-lined pie pan and set aside.
3In medium saucepan, combine water, sugar, and cream of tartar. Stir well and bring to a boil. Reduce heat and simmer for 15 minutes. Remove from heat. Stir in vinegar.
4Cool sugar mixture, then pour over crackers. Dot crackers with butter and sprinkle with cinnamon. Cover with second pastry shell. Seal edges and cut steam vents in top.
5Bake in preheated oven for 30 minutes or until crust is golden brown. Cool and serve with ice cream or whipped cream if desired.