1. Add a few drops of green food coloring to the mashed potatoes in a large mixing bowl.
2. Mix together well.
3. Mix in the salt, sugar, vanilla, coconut and butter.
4. Knead dough for about 5 minutes.
5. If dough become too stiff add a pinch or 2 of sugar until dough reaches desired constituency.
6. Tear off sections of dough and roll into log shapes.
7. Place the cinnamon onto a piece of wax paper.
8. Roll each log through the cinnamon.
9. Place each log onto a piece of wax paper.
10. Let candy sit for 1 hour to firm.
11. Store in a sealed container.