Heat the oven to 300 F. Toss the pecans with the oil and spread them out on a large, rimmed baking sheet. Bake for 25 minutes or until lightly toasted. Remove the pan to a rack and let the pecans cool.
Place a large sheet of wax paper on the countertop. Combine the sugar, cinnamon, salt, and water in a saucepan and place it over medium heat. Stir until the sugar is dissolved and bring the mixture to a boil. Cook to 236 F or soft-ball stage. Remove the mixture from the heat, add the vanilla, and then add the pecans. Stir briskly until the mixture is creamy looking.
Turn the pecans out onto the wax paper and separate them with forks. They will be sticky at first but will dry to a lovely candy coating.