Preheat your oven to 350°F and Llne the baking pan with parchment paper. Brew a strong espresso and chop the chocolate.
In a small saucepan, heat the butter over medium heat, stirring constantly, until it is golden brown and slightl foams.
Remove the saucepan from the heat, add the chopped chocolate and espresso. Stir well until the chocolate is melted.
In a bowl, combine the granulated sugar, eggs, and vanilla extract. Stir to fully combine.
Slowly pour the butter-chocolate mixture into the sugar-egg mixture, stirring constantly.
Sift the flour and salt over the batter and gently fold it in.
Pour the batter into the prepared baking pan and smooth the top.
Bake the brownies on the middle rack for about 25-30 minutes. Shortly before the end of the baking time, insert a toothpick into the center. It should come out moist and slightly crumbly.
Let the brownies cool and then cut it into equal pieces before serving.
