Preheat your oven to 350°F (175°C). This ensures your brownies bake evenly and achieve that perfect fudgy texture.
Line a 9x9-inch baking pan with parchment paper, allowing some overhang on the sides. This makes it easy to lift the brownies out after baking.
In a medium saucepan over low heat, melt the 11 tablespoons of unsalted butter. Stir occasionally until fully melted and remove it from the heat.
Add the 1 cup of granulated sugar and 1 scant cup of cocoa powder to the melted butter. Stir until fully combined and smooth.
Mix in the 2 teaspoons of salt and 1 teaspoon of vanilla extract, ensuring everything is well incorporated.
Allow the mixture to cool slightly, then add the 2 large eggs one at a time, mixing well after each addition until the batter is smooth and glossy.
Gently fold in the ¾ cup + 1 tablespoon of all-purpose flour until just combined. Avoid overmixing to keep your brownies from becoming cakey.
Pour the brownie batter into your prepared baking pan. Use a spatula to spread it evenly.
Bake in the preheated oven for 20-25 minutes. Check for doneness by inserting a toothpick in the center; it should come out with a few moist crumbs.
Allow your cocoa brownies to cool in the pan on a wire rack. Once cooled, use the parchment overhang to lift them out and cut into squares.