Preheat your oven to 350°F (175°C).
Prepare an 8x8-inch baking dish by greasing it or lining it with parchment paper.
In a large mixing bowl, combine the almond flour, cocoa powder, erythritol, salt, and baking powder.
In a separate bowl, whisk together the melted butter, eggs, and vanilla extract until smooth.
Pour the wet mixture into the dry ingredients and stir gently until just combined. Fold in chocolate chips if using.
Spread the batter evenly into the prepared baking dish.
Bake in the preheated oven for 20-25 minutes, until a toothpick comes out with a few moist crumbs.
Let the brownies cool in the pan for at least 10 minutes before slicing into squares.