Method (cake)

1. Preheat your oven to 180ºC fan and line an 8 x 8 inch square cake tin with grease-proof paper. Allow the paper to hang over the tin slightly, this makes it easier to remove the cake when baked.
2. In a bowl, combine the dairy-free milk with the apple cider vinegar and whisk until fully combined. Set aside for 10 minutes to curdle. This creates a vegan ‘buttermilk’.
3. In a large mixing bowl, sift the flour, sugar, baking powder and bicarbonate of soda. Mix well to combine. Add the oil and vanilla extract into the ‘buttermilk’ and whisk to combine.
4. Add the wet ingredients into the dry ingredients and mix just to combine. 
5. Divide the batter into 3 bowls. Leave one bowl plain white (this will be the vanilla cake), add 1& 1/2 tablespoons of cocoa powder to the second bowl and mix. Add the strawberry flavouring and a small drop of pink food gel to the third bowl. You will end up with three batters- chocolate, vanilla and strawberry.
6. Spoon the batter into the lined tin, one colour at a time, then using a skewer, swirl the colours together.
7. Pop the cake into the middle of the preheated oven and bake for around 25-30 minutes. You will know it is done when you put a knife or skewer down the middle of the cake and it comes out clean and it’s springy to the touch. If batter comes off on the skewer, it needs more time to bake. To prevent burning, top the cake with some grease proof paper then return back into the oven.
8. Allow the cake to cool in the tin for 10 minutes then carefully transfer onto a cooling rack. Allow to cool fully before frosting. You can even place the cake in a sealed container once cool then frost the day after. It’s a very light sponge so be careful with it when removing from the tin.

Method (buttercream)

1. In a large mixing bowl, add in the dairy-free butter, whip until creamy. I use a stand mixer with a balloon whisk attachment, a hand mixer will work great too.
2. Sift in the icing sugar. Whip on high speed for a couple of minutes to incorporate it. Add a splash of dairy-free milk to get it to a smooth consistency. 
3. Divide the buttercream into three bowls. Leave one bowl plain white. Colour the second bowl with a drop of pink food gel and strawberry flavouring. 
4. Melt the dark chocolate and mix it into the third bowl. 
5. Transfer the buttercream’s into separate piping bags and pipe lines of the buttercream onto the top of the cake (as seen in the video here).
6. Using a pallet knife, carefully spread the buttercream out to merge the colours together. Don’t over mix.
7. Why not decorate the cake with some white sprinkles.