|Mix one small package of lemon Jell-O in one cup of hot water and add the juice of a lemon and 1/2 of the lemon rind grated. Refrigerate until the mixture is like syrup. Whip one can of evaporated milk (which has been in the refrigerator for a couple of days). Add 3/4 cup of sugar and 1/2 teaspoon vanilla extract to the milk. Mix the milk and the Jell-O mixture together. Roll about six graham crackers in a Ziplock bag with a rolling pin. Spread these cracker crumbs on the bottom of a two-quart Pyrex dish. Pour the lemon mixture in the dish over crumbs. sprinkle more cracker crumbs on top (about six more crackers). Refrigerate a few hours until set.