Step 1

Simply mix all the ingredients together, except the vanilla extract, in a saucepan on a medium boil.

Step 2

Once the mixture has thickened and is bubbling slightly, after approximately 5 minutes, remove from the heat and stir in the vanilla extract.

Step 3

Use the sauce straight away or keep refrigerated for up to a week. The sauce will "set" when it's cooled so you will probably need to reheat it for it to regain a pourable consistency.