Place the medium saucepan over medium heat and melt the unsalted butter for about 1 minute.

Add the packed brown sugar to the melted butter and stir constantly for 2 to 3 minutes until the mixture bubbles and turns a rich amber color.

Remove the saucepan from heat and slowly pour in the heavy cream while stirring constantly for about 1 minute until fully combined.

Stir in the sea salt and vanilla extract until fully combined, about 30 seconds.

Let the caramel cool in the pan for 2 to 3 minutes until warm but not piping hot.

In a mixing bowl, add the softened cream cheese and pour the warm caramel over it, stirring until smooth, about 1 to 2 minutes.

Gently fold in the caramel sauce with a spatula until swirled, about 30 seconds.

Transfer the dip to a serving bowl and sprinkle with ground cinnamon and fleur de sel if desired; serve immediately warm or refrigerate until ready to serve.