Pour chilled evaporated milk into large mixing bowl; beat with electric mixer until the milk doubles in size. Gradually add the sugar while still beating and then pour in the lemon juice. The mixture will then thicken.
Into a Pyrex dish (either square or rectangular) pour enough vanilla wafers to line or cover the bottom, then pour your mixture in. With remainder of vanilla wafers, sprinkle over the top of the mixture. Place in refirgerator for a few hours before serving.
Note: On this recipe I make it in layers like a banana pudding instead of doing just one layer.