Preheat the oven to 350°F (175°C). Grease and line an 8×8 square pan with parchment paper, allowing an overhang for easy removal later.

In a small saucepan over medium-low heat, combine the butter and ⅔ cup of the sugar. Stir frequently until the butter is melted, and the sugar is almost dissolved. The mixture should be glossy and smooth. Set aside to cool.

In a separate bowl, vigorously whisk the eggs with the remaining 1 cup of sugar until the mixture begins to foam and the sugar is well incorporated.

Gradually whisk the cooled butter mixture into the egg mixture. Ensure the butter isn’t too hot to prevent cooking the eggs.

Sift together the all-purpose flour, cocoa powder, and salt over the batter.

Gently fold the dry ingredients into the wet mixture until fully incorporated. Be careful not to over mix; it’s okay if a few streaks remain.

Fold in the chocolate chips and pour the batter into the prepared pan. Optionally, top with additional chocolate chips for extra indulgence.

Bake for 30 to 35 minutes, or until the top is set with a few cracks. Avoid overbaking, as this could make the brownies dry.

Allow the brownies to cool completely on a wire rack before gently pulling them out of the pan using the parchment paper overhang.

Once cooled, transfer to a serving plate and cut them into squares to serve.