Preheat the Oven: Preheat your oven to 350°F (175°C). Grease or line a 9x13 inch baking pan with parchment paper for easy removal.
Mix the Wet Ingredients: In a large mixing bowl, combine the melted butter, granulated sugar, and brown sugar. Stir until smooth. Then, add the eggs one at a time, mixing well after each addition, and stir in the vanilla extract.
Combine the Dry Ingredients: In a separate bowl, whisk together the all-purpose flour, cocoa powder, and salt.
Incorporate the Ingredients: Gradually add the dry ingredients to the wet ingredients. Stir just until combined; be careful not to overmix. If using, fold in the chocolate chips.
Bake: Pour the batter into the prepared baking pan and spread it evenly. Bake in the preheated oven for 20-25 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs.
Cool and Serve: Allow the brownies to cool in the pan before cutting them into squares. Enjoy them warm or at room temperature for that perfect chewy texture!