Add sugar to a medium-size saucepan over medium-high heat. Cook the sugar, constantly stirring until it is completely melted. This will take about 5 minutes.
Add the pecans and stir until the melted sugar completely coats the pecans.
Remove the pan from the heat and add the vanilla. Stir to combine.
Turn the pecans out on a silicone non-stick baking mat or piece of parchment paper, and spread out in an even layer.
When the pecans are cool, break apart and store in an airtight covered container for up to two weeks on your kitchen counter.
Sharon's Expert Tips:*You can buy pecans already roasted, but if you want to roast them yourself, check out my recipe for How to Roast Pecans.To freeze pecans, cool completely, then store in an airtight container for up to 2 months in the freezer.Pecans, as well as other nuts, will last much longer if you store them in the refrigerator or freezer and won't turn rancid as quickly.Nutrition information is for 1 cup of candied pecans.[nutrition-label]