In a large sauce pan over medium heat, combine evaporated milk, sugar, water and vanilla.
Heat mixture, stirring often, until sugar is dissolved.
Add cinnamon and stir. Some may float on top.
Add 3 cups of pecans to mixture and stir to cover.
Continue stirring pecans in mixture until pecans become coated well and mixture cooks away (gets absorbed/crystalized on the the pecans).
Spread hot coated pecans on wax paper; try to separate them as you spread them on the paper.
Let pecans cool completely.
Break apart pecans and store in air-tight container for up to 2 weeks.
To give as gifts, put in decorative glass jars or decorative tins lined with wax paper.
NOTE: I've tried using brown sugar (1:1 with the white sugar), but the pecans have a tendency to come out sticky and the sugars don't get 'crystalized'. I have not tried these with turbinado or unbleached cane sugar yet. If they don't turn out right, I'll have to keep them for myself !