Preheat oven to 350°F.
Prepare an 8-inch-square baking pan: cover parchment paper, allowing it to slightly overhang opposite ends.
Cream butter, tahini and almond butter in a mixing bowl with an electric mixer until creamy.
Add in eggs, brown sugar and vanilla, mix well.
Whisk almond flour, baking powder and salt in a small bowl.
Add the flour mixture into the wet ingredients until just combined.
Stir in chocolate chips.
Spread the batter evenly into the prepared pan.
Top with additional chocolate chips as desired.
Bake 25-30 minutes, until a toothpick inserted into the center comes out clean. As with all gluten-free baking, if the top seems brown enough but you want the center to cook a bit more, loosely cover with foil and return to oven.
Let cool in the pan for 45 minutes. Lift the entire parchment paper out and transfer to a cutting board. Cut into 16 squares.
Store in a sealed container in the refrigerator for up to a week or two. Freeze well too!