Preheat oven to 350º F.
Coat a 10-inch bundt pan with a little avocado oil. Dust with flour, tapping out any excess.
Place the chocolate and cocoa powder in a glass or stainless steel bowl over a double boiler. Stir gently until melted and combined. Remove from heat.
In the bowl of an electric mixer fitted with a paddle, mix the all-purpose and almond flours, cinnamon, salt, baking soda and baking powder at low speed.
In a separate bowl whisk the mashed avocado, avocado oil, water, vinegar, vanilla extract and both sugars.
Slowly incorporate the wet ingredients to the dry ingredients until just incorporated.
Add the chocolate and beat until fully incorporated.
Pour the batter into the prepared pan and bake in preheated oven for 1 hour, until a toothpick inserted into center of cake comes out clean. Allow to cool.
While the cake is baking, prepare the chocolate ganache. Heat the heavy cream and vanilla extract in a small saucepan until it starts to simmers.
Remove from heat, add the chocolate and stir until melted and smooth.
When the cake cools, invert onto a platter and pour the warm ganache over it. Dust with powdered sugar and serve.