Combine ¼ cup water and ½ cup sugar in a medium saucepan over medium-high heat. Stir until dissolved, about 5 minutes or so.
Cover and boil, about 3 minutes. Remove the lid and stir consistently until the mixture is a light amber color.
Remove from heat immediately, then stir in remaining ¼ cup water and vanilla.
If desired, add a pinch of salt for salted caramel syrup.
Stir in an airtight container in the fridge for up to 1 month.
Notes
Focus on your syrup and don’t allow any distractions. It’s very easy to turn your caramel syrup into burnt sugar syrup. As soon as the caramel syrup turns an amber color, remove it from the heat immediately. It will still cook a little more after you remove it from the heat, which makes it that much easier to burn. Once it’s burnt, you can’t save it and you’ll have to start over. (Ask me how I know!)This recipe makes around ¾ cup, but I wouldn’t double it until you’ve mastered this recipe.