You can skip this part if you have a store bought graham cracker crust on hand. Crush graham crackers, add sugar and cinnamon and mix well. Add the melted butter and mix thoroughly. With the back of a tablespoon, press mixture into the bottom and sides of a buttered 8-inch pie pan. DO NOT BAKE.
In a bowl, mix condensed milk with egg yolks and lemon rind. Pour in the lemon juice and stir to a smooth consistency, allowing the juice to "curdle" and "cook" the eggs and milk. Pour into the graham cracker shell and refrigerate.