In a medium saucepan over medium heat, combine white chocolate chips and half-and-half.
Stir frequently until the ingredients are combined and the chips are fully melted, with no lumps remaining. Remove from heat.
Stir in the vanilla extract.
Let cool. Store in an airtight container in the fridge.
Notes
Here are some tips and tricks for making this recipe:
Whether you use white chocolate chips or bars, weigh the white chocolate for the right ratio to half-and-half.
For a thicker syrup, use heavy cream. For a thinner syrup, use whole milk.
Keep the heat at medium or even medium-low. White chocolate burns quickly, and there’s no going back once it burns. Cook the mixture until the chips are just melted.