In a small saucepan over medium heat melt butter. Once butter has completely melted, add sugar, heavy cream, coffee powder and salt. Whisk until all of the coffee powder has dissolved.

Bring mixture to a slow boil, whisking constantly. Turn down heat to low and simmer and whisking for an additional 3 minutes to thicken.

Remove caramel sauce from the heat and add the vanilla extract. Stir to combine.

Serve warm, at room temperature, or pour into a glass jar and refrigerate for later use. The caramel sauce will thicken once it cools. The sauce will keep refrigerated for 2 to 3 weeks.

To rewarm, microwave on low in bursts of 15 to 30 seconds, stirring between each session, until heated. Or reheat gently over low heat in a saucepan.