Preheat your oven to 350°F (175°C), prepping a cozy environment for those fudgy brownies to bake perfectly.

Lightly spray a 9×9" metal baking pan with non-stick spray.

In a microwave-safe bowl, melt the semi-sweet chocolate chips and salted butter together. Stir occasionally until smooth, then let it cool slightly.

In a small bowl, sift together the all-purpose flour, cocoa powder, espresso powder, and salt.

In a large bowl, combine the eggs, granulated sugar, and vanilla. Mix with an electric mixer on medium speed for about three minutes.

Gently fold the cooled chocolate and butter mixture into the egg mixture.

Tip in the dry ingredients and gently fold until just combined.

Pour the batter into the prepared pan, spreading it evenly. Bake in the preheated oven for 34-40 minutes.

Let your brownies cool completely in the pan for at least three hours.

Once cooled, remove the brownies from the pan and cut them into 16 squares.