Preheat the oven at 180°C.Line cake pans with baking paper, grease and powder them with flour.
Pour 1 cup of soy milk in a glass then add the cider vinegar and the lemon juice. Let it curdle for about 5 minutes.
In a bowl add the coffee and the butter. Let the butter melt [7].Then stir together the sugar, the apple sauce, the vanilla powder, the vanilla extract and the water.
Mix together the sifted flour, cocoa, baking powder, baking soda and salt.
Add the liquid mix to the dry one and gently stir together with a spatula.
Pour the dough evenly in the 3 baking pans.
Bake in the oven (middle section) for 35 minutes or until a toothpick inserted into the cake comes out clean.Once baked, let the cake cool down a few minutes before removing from the pan.The cake must be completely cooled before dressing with the buttercream.
Buttercream
Cream the butter with a hand mixer or the paddle attachment of a stand mixer until smooth and fluffy.
Gradually beat in the icing sugar until fully incorporated.
Gradually beat in the cocoa until fully incorporated.
Beat in the melted chocolate (once cooled).
Beat in the vanilla powder and the vanilla extract.
Pour the 30ml of milk and beat again for 1 or 2 minutes.The buttercream should be smooth and glossy.
Transfer the buttercream to a piping bag [8] and keep into the fridge until the cakes are totally cooled down.
Then start by pipping a ¼ of the buttercream on top of one layer. Then put the second layer and use another ¼. Place the third layer and use the rest of the buttercream to frost the top and the sides of the cake using an angled palette knife.
Notes
[1] If you don't have 3 cake pans, you will have to bake them separately.[2] This is optional, if you don't want to use coffee you can replace it by hot water.[3] If you don't have apple sauce at hand, you can replace it by another fruit sauce, or plain vegan yogurt (the texture and taste of the cake might change a little).[4] If you don't have vanilla powder you can add more vanilla extract.[5] If you don't have cream flour you can use cake flour or plain flour + 1 tbsp of cornflour + 1/2 tsp of baking powder.[6] Once the chocolate is melted leave it aside a couple of minutes to cool down.[7] To help the butter melt you might need to microwave the mix a few seconds at a time.[8] For a naked look there is no need for a nozzle. If you plan making decoration as well you may wish to use the adequate nozzle.[9] In order to get the best result the buttercream needs to stay a couple of minutes out of the fridge before using it to frost the cake.