Preheat your oven to 350°F (175°C).
Line your 9x13-inch baking pan with parchment paper.
Melt the butter in a large mixing bowl and allow it to cool slightly.
Add the sugar to the melted butter and whisk until combined. Then, add the eggs one at a time, mixing thoroughly after each addition, followed by the vanilla extract.
In a separate bowl, sift together the cocoa powder, flour, baking powder, and salt.
Gradually add the dry mixture to the wet ingredients, folding gently until just combined.
Pour the brownie batter into the prepared baking pan and spread it evenly.
Bake for 25-30 minutes or until a toothpick inserted in the center comes out with a few moist crumbs.
Let the brownies cool in the pan for at least 10 minutes, then lift them out using the parchment paper and cool completely on a wire rack before cutting into squares.
