In a large mixing bowl, whisk together the vegan buttermilk and hot coffee until smooth. Gradually sift in the all-purpose flour, cocoa powder, sugar, and baking powder. Mix until just combined; be careful not to overmix for a light cake.

Preheat your oven to 350°F (180°C) and grease three 8-inch cake pans. Divide the prepared batter evenly among the three pans, smoothing the tops with a spatula. Bake for approximately 40 minutes, or until a toothpick inserted into the center comes out clean.

While the cakes cool, melt the vegan butter in a saucepan over medium heat. Stir in the coconut flakes and pecans, cooking until the mixture thickens and bubbles slightly, about 5–7 minutes.

Prepare your vegan chocolate ganache by combining dairy-free chocolate and heated plant-based milk, stirring until smooth. Next, prepare the chocolate buttercream by whipping together softened vegan butter, cocoa powder, and powdered sugar until creamy.

Once the cakes have completely cooled, place one layer on a serving plate. Spread a layer of coconut pecan frosting on top, followed by a drizzle of ganache. Add the second layer and repeat. Finish with the third layer on top and frost the top and sides with chocolate buttercream.