Preheat the oven to 180°C/160°C Fan/Gas Mark 4. Grease and line 2 x 8” round cake tins. Combine the soy milk and lemon juice in a small bowl, it should begin to curdle and leave to one side.
Place the flour, Baking Powder, Bicarbonate of Soda, Cocoa Powder and sugar in a bowl and mix together until well combined and make a well in the centre. In a separate bowl mix together the apple sauce and 1 tsp of baking powder.
Pour the oil, Vanilla Extract and apple sauce mixture into the dry ingredients and whisk together until just combined then add the soy milk mixture and whisk into the batter.
Divide the batter equally between the 2 prepared cake tins and bake for 30-35 minutes until risen and a skewer inserted into the centre comes out clean. Leave to cool in the tins for 15 minutes and then transfer to a wire rack to cool completely.
Once the cakes are cool using a serrated knife cut to domed top off one of the cakes and place on a cake board or serving plate.
Stir the Buttercream in the tub to loosen. Spread half the tub of buttercream over the layer of sponge on the serving plate. Place the other layer of sponge on top and sandwich together.
Spread the remaining buttercream on the top of the cake. Finish the cake with a sprinkling of finely chopped chocolate!