Preheat the oven to 355°F (180°C) and grease three 8’’ cake pans with oil or vegan butter and line the bottom with parchment paper. Set aside.

In a medium bowl, whisk all-purpose flour, natural cocoa powder, black cocoa powder, cornstarch, baking powder, baking soda, ground coffee, and sea salt. Set aside.

To a large bowl, add sunflower oil, granulated sugar, vegan yogurt, and apple cider vinegar, and whisk to combine. Sift in half of the dry ingredients and mix until almost incorporated. Sift in the remaining flour and mix until incorporated. Then add boiling water and gently mix until combined.

Divide the batter evenly into the cake pans, and bake in preheated oven for 30 minutes, or until the toothpick inserted in the middle comes out clean. Remove from the oven and let cool for about 10-15 minutes in the pan, then transfer the cakes to a cooling rack to cool completely.

Add soft vegan butter to a large bowl (alternatively, add the vegan butter to a stand mixer with the whisk attachment) and cream with a hand mixer on high speed until fluffy and lighter in color for about 2-3 minutes. Then sift in about ½ of powdered sugar, and mix until combined. Keep gradually adding the remaining powdered sugar and mix until fully combined. While mixing, add one tablespoon at a time of almond milk and mix until incorporated and fluffy. Finally, add the Oreo crumbs and mix gently with a spatula until incorporated.

Using a sharp knife or thread, slice the top of the cakes, ensuring each is evenly flat.

Place one cake layer on a cake stand or serving plate and spread a layer of frosting on the top, followed by 2 roughly crushed Oreos. Place the next cake layer on the frosting making sure it is level. Again, frost the top and add crushed Oreos. Then gently place the third layer (the bottom upwards), making sure it is level. Spread a thin layer of frosting on the sides and top of the cake and scrape away any excess using a cake scraper (at this point, you should have about half of the buttercream frosting left). Let the cake chill in the fridge for about 45-60 minutes.

Remove cake from the fridge and finish frosting with a thick layer of buttercream frosting around the sides and the top (leave some frosting for decoration on top of the cake). Place the cake in the fridge to chill again while you make the ganache.

Place finely chopped dark chocolate bar in a glass bowl, and put it over a small pot with just-boiled water. Don't let the bottom of the bowl touch the hot water. Let the chocolate slowly heat up and melt. Mix it through a few times. Once the chocolate is melted, slowly and gradually, while stirring, mix in vegan cooking cream (use spatula or spoon, don’t use a whisk because it would create bubbles). Stir until combined into a smooth ganache.

Fill a squeezing battle with a warm chocolate ganache and create a drip on the edge of the cake. Once you’ve gone around the edge, cover the top with the remaining ganache. Place in the fridge to set. Use the remaining frosting to pipe swirls around the top of the cake, adding 12 Oreo cookies in between.

Slice and enjoy!