Pre measure all your ingredients and have them ready to go.
In a sauce pan, melt the butter over medium heat.
Add the cream and brown sugar and stir until the sugar disolves. Once the sugar disolves simmer for 4-5 minutes without stirring. Reduce the heat a little if it turns into more of a boil than a light simmer.
Remove from heat and whisk in the vanilla, cinnamon and salt.
Pour into a heat proof container to cool. The sauce will thicken as it cools.
Store the sauce in an air tight container in the fridge for up to two weeks. We like to use mason jars because you can pour the hot sauce directly into the jar and then screw the lid on to store.