Preheat your oven to 350 degrees Fahrenheit. Grease a 9x9-inch metal pan with non-stick spray and set it aside.

Melt the semi-sweet chocolate chips and salted butter together, then set the mixture aside to cool slightly.

Sift together the flour, cocoa powder, espresso powder, and salt in a small bowl, then set it aside.

In a large bowl, mix the eggs, granulated white sugar, and vanilla with an electric mixer for three minutes until pale in color.

Gently fold the melted chocolate and butter into the sugar/egg mixture until combined.

Add the dry ingredients to the mixture and gently fold them in until combined.

Pour the batter into the prepared pan and bake for 34-40 minutes, or until the center only wobbles slightly when shaken.

Allow the brownies to cool completely for at least three hours before cutting them into squares. This allows them to finish baking and ensures the perfect texture.