Mix the sugar, baking soda, buttermilk and salt in saucepan. Cook and stir for 5 minutes over medium heat. Add the butter and pecans and cook until mixture reaches the soft-ball stage (235 degrees F.)
Remove the pan from heat, cool and beat with a wooden spoon until creamy. Add the vanilla, and drop by spoonfuls onto waxed paper.
Notes
If you are preparing this recipe as gluten-free, be sure to use a brand of vanilla that is known to be GF.