Preheat your oven to 350°F (175°C). Grease a 9x13-inch baking pan or line it with parchment paper for easy removal.
In a medium saucepan, melt the butter over low heat. Once melted, remove from heat and stir in the sugar until well combined.
Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.
In a separate bowl, whisk together the cocoa powder, flour, salt, and baking powder. Gradually add the dry ingredients to the wet mixture, stirring until just combined. If desired, fold in the chocolate chips.
Pour the brownie batter into the prepared baking pan, spreading it evenly. Bake for 25-30 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs.
Allow the brownies to cool in the pan for at least 15 minutes before cutting into squares. Enjoy!