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

Melt butter and chocolate together in a saucepan over low heat, stirring until smooth. Remove from heat.

Stir in sugar, eggs, and vanilla extract.

In a separate bowl, whisk together flour, salt, and instant coffee or espresso powder.

Gradually add the dry ingredients to the chocolate mixture, stirring until well combined.

Pour batter into the prepared pan.

Dollop caramel sauce on top and use a knife to swirl it into the batter.

Bake for 25-30 minutes, or until a toothpick inserted in the center comes out with moist crumbs.

Let brownies cool completely before cutting.

Sprinkle with sea salt before serving.