Preheat oven to 350° F. Line an 8" x 8" baking dish with parchment paper.
In a large bowl, beat the butter and coconut sugar with an electric beater until combined. Add in ½ cup cashew butter, egg, and vanilla extract and beat with the electric beater on low/medium until combined completely.
Add the almond flour through the cream of tartar and use a spoon to stir until just combined. The batter will be very thick. Fold in the chocolate chips. Use the spoon to transfer the batter into the parchment paper lined baking dish. Distribute the remaining ¼ cup of cashew butter over the top of the brownies and use a knife to swirl the cashew butter into the batter a little bit. Use the spoon to even out the batter in to a uniform thickness.
Bake at 350° F for 25 - 28 minutes, until a toothpick inserted comes out dry (small crumbs are okay as long as they are not wet). You may have to try a few different spots to make sure you are getting the batter and not a melted chocolate chip. Let cool almost completely. Cut into 16 squares and enjoy!
