Preheat oven to 350°F. Line a 9”X9” square metal baking pan with parchment paper or aluminum foil. Melt butter and set aside till cool.
Whisk together butter, granulated sugar and vanilla extract in a large mixing bowl. Whisk in eggs, stirring until fully incorporated.
Add dry ingredients (baking soda, salt, flour and cocoa powder) to wet ingredients. Stir until combined. Fold in chocolate chips. Batter will be thick.
Spread batter into prepared pan. Bake at 350°F for 25-30 minutes. Let cool for 30 minutes before cutting.
Notes
Let the brownies cool completely in the pan before cutting for clean, sharp edges.