In a small saucepan, warm the cream, vanilla bean paste, and fine sea salt over low heat until steaming. Do not boil.

Meanwhile, stir together granulated sugar and water in a medium saucepan.

Cook over medium-high heat, stirring until the sugar dissolves, then stop stirring.

With a pastry brush, brush down sides of pan with water.

Bring to a boil. Allow caramel to cook, without stirring,*until it turns golden brown and resembles honey, about 6 minutes.

Whisk the butter and allow it to melt.

Remove from heat and whisk in the warm cream. (Be careful—it will bubble and splatter!)

Transfer to a bowl. Allow to sit at room temperature for 15-30 minutes. Use warm.

Allow remaining sauce to cool completely. Store in an airtight container in the refrigerator for up to 2 weeks.