Preheat oven to 356F (180C) and prepare an 8x8 brownie pan.
In a medium bowl, whisk the eggs.
Add the natural cashew butter, avocado oil, brown sugar, maple syrup, and vanilla extract. Whisk well until the liquid ingredients are fully combined.
Add the dry ingredients: cacao powder, salt and baking powder. Mix with a spatula until incorporated.
Stir in the dark chocolate chips (the batter will be thick!).
Spread the brownie batter on the prepared brownie pan and bake for 20 minutes.
Let the brownie cool down for 20 minutes before cutting.
Sprinkle additional sea salt on top if desired, enjoy them warm or save for later!