In a large skillet, combine the pecans, syrup, vanilla, salt, and cinnamon. Cook over medium heat for 8 to 10 minutes, stirring continuously, until the maple syrup begins to caramelize and the pecans are toasted.
4 cups pecan halves, ¾ cup pure maple syrup, ½ teaspoon pure vanilla extract, ¼ teaspoon salt, ¼ teaspoon ground cinnamon