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 microwave-safe bowl or on the stovetop, melt the butter until it's smooth. Allow it to cool slightly.
In a large mixing bowl, combine the sugar and eggs. Beat them together until the mixture is smooth and slightly pale.
Stir in the vanilla extract, incorporating it evenly into the sugar and egg mixture.
In a separate bowl, sift together the flour, cocoa powder, baking powder, and salt. Gradually add this dry mixture to the wet ingredients, mixing until just combined. Be careful not to overmix.
Pour the slightly cooled melted butter into the batter and stir until smooth. This will give your brownies a rich and velvety texture.
For an extra layer of indulgence, fold in chocolate chips or chunks into the batter. This step is entirely optional but highly recommended for chocolate lovers.
Pour the batter into the prepared baking pan, spreading it evenly with a spatula.
Place the pan in the preheated oven and bake for approximately 25-30 minutes or until a toothpick inserted into the center comes out with a few moist crumbs (but not wet batter).
Allow the brownies to cool in the pan for about 15 minutes, then transfer them to a wire rack to cool completely. Once cooled, cut into squares or rectangles.
Serve your decadent fudge brownies on a plate, and savor each heavenly bite. Pair them with a scoop of vanilla ice cream or a dollop of whipped cream for an extra treat.