Preheat your oven to 350°F (175°C). Grease a 9x13 inch baking pan or line it with parchment paper for easier removal.

In a medium saucepan, melt the butter over low heat. Remove from heat and incorporate the granulated sugar, stirring until well mixed.

Add the eggs one at a time, ensuring each is fully integrated before adding the next. Stir in the vanilla extract.

Gradually fold in the flour, cocoa powder, and salt, mixing until just combined. Be careful not to overmix.

Pour half of the brownie batter into the prepared baking pan and spread it evenly across the bottom.

Drizzle the caramel sauce over the batter, then carefully layer the remaining brownie batter on top.

Using a knife, gently swirl the caramel into the batter to create a marbled effect.

Bake in the preheated oven for 30–35 minutes or until the edges start to pull away from the pan. A toothpick inserted in the center should come out with a few moist crumbs.

Sprinkle flaky sea salt on top immediately after removing from the oven, allowing it to melt slightly into the warm brownies.

Allow the brownies to cool in the pan for at least 15 minutes before cutting them into squares.