Place walnuts in a food processor and pulse to break down in to a rough meal.
Add cacao powder and pulse again to combine.
Add the dates, vanilla and salt and process until the mixture starts binding together. Add one tablespoon water and pulse to combine.
Test the mixture by pinching some between your finger and thumb. It should be moist and hold together without a crumb texture. If crumbs, add another tablespoon of water and pulse again.
Press this mixture into a parchment lined square or round pan.
Make the ganache by melting the coconut oil, adding the maple syrup and cacao powder and whisking until it turns thick, smooth and shiny.
Add in the tahini and use a whisk to completely incorporate. It will be thick, whisk until smooth.
Pout over brownie and smooth with spatula. Sprinkle with cacao nibs.
Chill for 2 hours before cutting and serving. Enjoy!