Preheat the oven to 350ºF (175ºC).
Grease an 8X8 pan and line with parchment paper.
In a stand mixer, cream the butter and sugar together.
Add eggs one at a time, making sure each is well incorporated before adding the next.
Add the vanilla.
In a separate bowl, whisk together the almond flour, cocoa powder, baking powder, and salt.
Add the dry ingredients to the butter mixture. Do this in batches so the dry ingredients don't come flying out of the bowl.
Pour mixture into the prepared pan. Using a spatula, make sure the batter is well into the corners.
Bake for about 35 minutes, until a toothpick in the middle comes out with a few sticky crumbs on it.
Cool completely. Turn out of the pan and cut.