Line a 13X9 baking pan with parchment paper.
Preheat your oven to 350 F.
Mix together the flour, baking powder, and salt and set aside.
Melt your butter in the microwave.
Add into the butter, the cocoa, sugar, and eggs (mix well with a spatula, scraping down the sides of the bowl.
In the same bowl as the butter mixture, add in the flour mixture, a little at a time, making sure you are mixing it together well.
Spread into the pan.
Bake for 20 minutes.
Let it cool.