Preheat your oven to 350°F (175°C). Grease a 9x13-inch baking pan.

In a large mixing bowl, combine softened unsalted butter, granulated sugar, and brown sugar. Beat until light and fluffy, about 2-3 minutes.

Mix in 1 teaspoon of vanilla extract, then gradually add flour and salt, mixing until combined.

Transfer the batter to the greased baking pan and spread it out evenly.

Bake for 25-30 minutes, or until the edges are golden brown and a toothpick comes out clean.

In a saucepan over medium heat, combine heavy cream and unsalted butter until melted and smooth.

Remove from heat and stir in another teaspoon of vanilla extract and sea salt.

Once the bars are out of the oven, pour the caramel sauce evenly over the top.

Allow the bars to cool completely at room temperature, then cut into squares.