Preheat oven to 350ºF (175ºC).
In a food processor, blitz butter, salt, flour, sugar, cocoa powder, vanilla extract and soy milk until uniform and a dough forms. Press into a well-greased 8-inch tart pan and use a fork to pierce the shell all along the bottom and edges to prevent the crust from bubbling up. Feel free to use pie weights if you have them, but it’s not necessary.
Bake for 10-12 minutes until the bottom looks baked (it’ll be slightly bubbled, and just slightly more browned than the rest of the tart shell). Remove from oven and let cool completely on a wire rack.
Meanwhile, melt chocolate and coconut oil in a heat-safe bowl over a pot of simmering water (or simply a double boiler). Set aside.
To prepare the filling, use a food processor or a blender to mix avocado, maple syrup melted chocolate, avocados, and vanilla extract until uniform and whipped in texture. Fill cooled tart shell and let set in the fridge for at least 2 hours. To serve, garnish with toasted coconut flakes, fresh avocado slices, coconut whipped cream or fresh raspberries and enjoy!
To store, cover with plastic wrap in the fridge and eat within a week.