In a medium heavy-duty stainless steel saucepan, melt the 4 tablespoons Butter over medium-heat on the stovetop until it is fully melted.
4 tablespoons Butter
Add the 1 Cup Brown sugar and Pinch Salt to the saucepan. Stir until well combined.
1 Cup Brown sugar, Pinch Salt
Heat the brown sugar, butter and salt over medium heat for about 4 minutes, it will start melting together and bubble vigorously.
Carefully stir in the 1/2 Cup Heavy whipping cream to the melted sugar and increase heat to medium-high heat.
1/2 Cup Heavy whipping cream
Pay close attention while you simmer the mixture, stirring often for about 5-6 minutes.
(If you use too high of heat, it will turn into toffee.)
Once the caramel sauce has thickened, remove from heat.
Add in the 1/2 tablespoon Vanilla Extract and stir it in till fully incorporated.
1/2 tablespoon Vanilla Extract
(It will bubble up some as the alcohol evaporates.)
Pour into a glass jar or airtight container for storage.
(A mason jar works well. See storage tips below.)
The hot caramel will be thin at first but as the caramel cools it will thicken as it comes to room temperature.
