Preheat your oven to 350°F (175°C). Lightly grease a 9x13-inch baking pan with butter or line it with parchment paper. This will ensure the brownies don’t stick and come out neatly when cooled. Getting your pan ready first makes the process smooth.
In a saucepan over medium heat, melt the butter until fully liquid. Remove it from the heat and stir in the sugar while still warm. This step helps create a glossy finish on the brownie top. Let it cool slightly so the eggs won’t scramble when added later.
Crack the eggs into the butter-sugar mixture one at a time, mixing well after each addition. This ensures they blend smoothly, giving the batter structure. Stir in vanilla extract, which enhances the chocolate’s flavor and adds a sweet aroma.
In another bowl, whisk together the flour, cocoa powder, and salt. Gradually fold this dry mixture into the wet batter. Do not overmix; just stir until the flour disappears. Overmixing can make brownies dense instead of soft and fudgy.
Pour the brownie batter into the prepared pan and spread evenly. Drizzle caramel sauce across the top in lines or spoonfuls. Use a knife or toothpick to swirl the caramel into the batter, creating a marbled effect. Set aside a little caramel if you want extra topping after baking.
Bake the brownies for 25–30 minutes. A toothpick inserted in the center should come out with moist crumbs, not raw batter. Remove the pan from the oven and let brownies cool completely before slicing. This cooling step helps the caramel set and makes cleaner cuts.
Once cooled, cut the brownies into squares. You can drizzle with the reserved caramel sauce or sprinkle nuts on top before serving. These brownies are delicious as they are, but pairing them with a scoop of vanilla ice cream takes them to the next level.