Coconut and chocolate stripey cake

This cake was made for my mums birthday, I first saw it on Fiona Cairns fabulous cakes, she was the lady that created the Royal wedding cake. I personally think she comes across as really patronizing but she sure knows a lot about baking!

For the cake:
350g unsalted butter, really soft, diced, plus more for the tins
2tbsp cocoa powder
350g self-raising flour
2tsp baking powder
6 eggs, lightly beaten
350g golden caster sugar
2tsp vanilla extract
90g creamed coconut, grated, or grated fresh coconut

For the coconut frosting:
300g cream cheese
150g icing sugar
45g creamed coconut, grated, or grated fresh coconut
1tsp vanilla extract
For the buttercream:

150g 70% cocoa solids chocolate
225g unsalted butter, softened
300g icing sugar, sifted
1tsp vanilla extract

Bit of a lengthy one but worth it!

Method:
Preheat the oven to 180°C/350°F/Gas Mark 4. Butter two 20cm round sandwich tins and line the bases with baking parchment. Make an 8cm high collar of baking parchment for each tin too. Mix the cocoa powder with 12 tbsp boiling water, and set aside to cool.

Sift the flour and baking powder into the bowl, add the butter, eggs, sugar and vanilla. Beat until well blended, taking care not to over-mix. Remove half the batter to another bowl.
Gently stir the coconut into one bowl and scrape into one of the tins.
Add the cocoa paste to the other, stir and scrape into the other tin.
Bake both cakes for 30,40 minutes, or until a skewer emerges clean.

Remove from the oven and leave the cakes for a minute or two, then run a knife around each to loosen it from the tin. Turn out on to a couple of wire racks. Remove the papers and leave to cool completely.
Meanwhile, to make the coconut frosting, place the cream cheese in a bowl. Sift over the icing sugar and whisk until well blended.

Add the coconut and vanilla and mix well. To make the chocolate buttercream, melt the chocolate in a heatproof bowl over barely simmering water, making sure the bowl does not touch the water. Set aside to cool.

Beat the butter until really pale and fluffy, then add the icing sugar and vanilla.
Beat for five minutes until light and creamy. Add the chocolate and beat again. Take a few spoonfuls and, with a palette knife, place into the icing bag. Only half-fill the bag, or it will make a mess.

Level the tops of the cakes, turn upside down and place on a work surface.(I cut each cake it half length way,as I was aiming for a checked effect) Cut the cakes into 2cm strips; each should make 10 strips. Alternate them so each cake has 10 strips of the two flavours (do this with both cake but alternate with the second eg if the first starts with coconut then chocolate start the other stripe chocolate then coconut!,

Using half the coconut frosting, sandwich together the strips of cake put the cake together and spread the rest over the top and sides. Rest in the fridge for an hour to firm up.

To decorate the cake, place it on to an upturned 15cm cake tin.
Pipe chocolate roses of varying sizes, from the inside outwards. Practice first on a small plate and scrape the buttercream back into the bag to re-use. Lift gently on to a serving plate.