In the bowl of your food processor, add the ingredients and pulse until they're finely ground and the mix begins to form a ball.
Press the mixture into the bottom of an 8 or 9" springform pan (making sure to pack it tight)
Chocolate Greek Yogurt Mousse
To the bowl of your stand mixer, add the heavy cream and whip until stiff peaks form.
Using a spatula, gently fold the Greek yogurt into the whipped cream.
Add the cacao powder, honey, and vanilla
Spread the mousse evenly over top the crust.
Cover and place in the fridge for 1½ hours
In a small saucepan over low heat, add the coconut milk and chocolate.
Stir continuously until the chocolate is melted and smooth.
Let cool five to ten minutes before pouring over the top of the mousse. (Test the ganache first. You're going for something pourable and spreadable, but not hot enough that it will melt the mousse)
Sprinkle with chopped hazelnuts.
Chill 30 minutes or until ready serve.
Run a knife around the inside of the springform pan and then release the cake from the pan. Slice and serve!