Line a baking sheet with parchment paper and set aside.

In a medium non-stick skillet, combine granulated sugar, butter, and water over medium heat. Stir until melted and smooth, about 2 minutes.

Add walnut halves and stir constantly for 3–5 minutes until coated and golden brown.

Remove from heat and stir in vanilla extract and salt.

Transfer walnut mixture to the prepared baking sheet and spread out in a single layer. Allow to cool completely.

Store in an airtight container or serve once cooled.