Preheat your oven to 350°F (175°C) and prepare an 8x8-inch baking dish by lining it with parchment paper.

In a large mixing bowl, combine almond flour, cocoa powder, baking powder, and salt. Whisk until well mixed.

In a separate bowl, whisk the eggs until pale and frothy. Melt the butter and mix in with vanilla extract and sugar.

Gently pour the wet mixture into the dry ingredients and stir until just combined.

Fold in the chopped dark chocolate or chocolate chips into the batter.

Spread the batter in the lined baking dish and bake for 20-25 minutes. The edges should be set, and the center will jiggle slightly.

Cool in the pan for at least 20 minutes before cutting into squares for serving.