Remove the butter from the fridge for about 20-30 minutes before use. Add the cocoa powder, salt, and sweetener to a bowl. Mix well to combine. Set it aside.
Step 2
Add the chocolate to a microwave-safe bowl. Microwave until completely melted. Remove from the microwave and cool for about 5 minutes.
Step 3
Add the softened butter and eggs to the chocolate. Using a hand mixer on medium speed, beat until fully combined. Note: The chocolate shouldn’t be too hot. Otherwise, the eggs will start to cook.
Step 4
Gradually add the cocoa mixture, beating constantly to combine. Finally, add the xanthan gum. Using a hand mixer on high speed, vigorously mix until the xanthan gum is completely combined with the batter.
Step 5
Roughly chop the walnuts. Fold in the walnuts to the mixture. Set it aside.
Step 6
Preheat the oven to 180°C (350°F). Line a small 20x20cm (8×8 inch) baking pan with parchment paper. Transfer the batter to the prepared baking pan and bake for 25 minutes.
Step 7
When done, remove it from the oven and cool it to room temperature. Cut into 9 equal pieces and serve immediately. Enjoy!