Preheat oven to 180°C and line 3x 6 inch cake pans with cooking spray and baking paper.
In a large bowl, whisk to combine eggs, brown sugar, white sugar, vanilla, and melted coconut oil. In a separate bowl, sift flour, cocoa powder, bicarbonate of soda, baking powder and salt and stir to combine. Add half of the dry ingredients into the wet and half of the coconut milk and whisk until combined. Add in the remainder of the dry ingredients along with the milk and again stir until mixture just comes together being careful not to overmix.
Divide the batter evenly between the 3 pans and place in preheated oven to bake for 20 minutes, or until the cake springs back when lightly pressed.
Take the cakes out of the oven and let cool in the pan for 10 minutes before turning out onto a wire rack to cool completely.
Make the buttercream. Using a hand mixer or a stand mixer with the paddle attachment fitted, beat dairy-free spread and vanilla for 1-2 minutes until creamy.
Add in 3 cups of icing sugar and cocoa powder and beat on medium until combined. As mixture thickens, add in coconut milk a tablespoon at a time. If frosting is too thin, add in an extra ½ icing sugar until it reaches a smooth and creamy consistency. Add pinch of salt to taste if frosting is too sweet.
Decorate the cake. Level the cakes with a large knife if they have domed in the oven. Place a small amount of the buttercream on a cake stand and place the first cake layer down. Add enough frosting to thickly cover the layer and add the second cake layer. Add more frosting, then the final cake layer upside down so the top of the cake is flat. Add more frosting to the top and side of the cake with a cake knife until its completely covered. Run a cake knife around the outside to smooth the edges.Top cake with fresh raspberries and chopped dark chocolate, or use the remaining frosting to pipe swirls around the top.