Gather all your ingredients and tools, including a saucepan and a baking sheet.
In a saucepan, combine sugar, water, vanilla extract, and salt.
Stir the mixture over medium heat until the sugar completely dissolves.
Add the pecans to the saucepan and stir until they are well-coated.
Continue cooking, stirring frequently, until the liquid reduces and becomes syrupy.
If using, sprinkle cinnamon over the pecans and stir to combine.
Remove the saucepan from heat and transfer the pecans to a baking sheet lined with parchment paper.
Spread the pecans out in a single layer to cool.
Allow them to cool completely, which will help them harden and become crunchy.
Once cooled, break apart any clusters and store in an airtight container.