01 - Preheat the oven to 350°F. Grease an 8x8-inch baking pan or line with parchment paper.
02 - In a medium bowl, whisk together almond flour, cocoa powder, baking powder, and salt until evenly mixed.
03 - In a large bowl, whisk melted butter, granulated sugar, brown sugar, eggs, and vanilla extract until smooth and glossy.
04 - Carefully fold the dry ingredients into the wet mixture until just combined, avoiding overmixing.
05 - Gently fold in the dark chocolate chips and nuts if using.
06 - Pour the batter into the prepared pan, smoothing the surface evenly.
07 - Bake for 23 to 26 minutes, testing with a toothpick inserted in the center; it should come out with a few moist crumbs.
08 - Allow brownies to cool completely in the pan before slicing into 16 squares.