Heat evaporated milk (1 large and 1 small can) and water (measure 1 large can and 1/2 small can) until it makes a scum on top.
Stir together 1 cup sugar and 4 eggs until smooth. Add milk if mixture is too thick.
Pour egg mixture into milk mixture (cooking on stove) slowly, stirring all the while. Cook about 5 minutes, stirring rapidly so mixture won't get lumpy. Mixture will get slightly thickened. Remove from heat. Add 1 tbsp. vanilla and 1 stick butter and stir.
Break enough crackers into sauce to make mixture thick and stir. (about 1 stack)
Hint:Crackers become soggy in pudding. When ready to eat, I'll serve myself a bowl and break a few more crackers into it and mix. This gives you two different textures.