brown sugar, firmly packed
1Combine sugars and sour cream in small saucepan. Cook over medium-high heat, stirring until mixture boils.
2Continue to boil until mixture reaches soft ball stage (240F) or forms a soft ball when dropped into cold water. Stir in salt and vanilla.
3Pour hot candy mixture over walnuts in a mixing bowl. Mix until walnuts are evenly coated.
4Spoon out onto waxed paper, separating walnuts.
5When dry, store in airtight container.