Put the oven on to 170c to preheat. Grease and line a deep 20cm cake tin.
Sift together the flour, bicarbonate of soda, baking powder, cocoa and salt.
Cream together the butter and the sugar. I used an electric food mixer. Beat for about a minute.
Add the eggs, one at a time and keep beating after each one. Then add the vanilla.
Add about ¼ of the dry ingredients. Beat together then add ⅓ of the buttermilk. Repeat until you have beaten all the dry ingredients and the buttermilk together.
Finally stir the food colour and vinegar together and add them to the cake mixture. Beat in until the mixture has all turned a pinky red colour without any streaks.
Pour the cake mixture into the cake tin and bake in the oven for about an hour. It is ready when a skewer inserted into the middle of the cake comes out clean
Leave the cake to cool in the tin.
Make the cream cheese icing by beating together the butter, cream cheese and icing sugar.
Take the cake out of the tin and slice into three layers horizontally.
Spread the icing on top of the bottom and middle layers. Put the layers back together and put the cake in the fridge for about 20-30 minutes for the icing to set.
To make the chocolate ganache icing put the dark chocolate, cream and liquid glucose in a bowl over a pan of boiling water. Keep giving it a stir until all the chocolate has melted. At the same time melt the white chocolate in a different bowl.
With the cake on a wire rack, pour the dark chocolate icing over the cake and use a palate knife to smooth it over the top and sides of the cake.
Put the white chocolate in a small piping bag or a plastic food bag. Snip off the corner and starting in the centre of the cake, pipe a chocolate spiral onto the top of the cake.
Using a cocktail stick or a thin knife, drag it through the chocolate starting in the centre of the cake.
Put it in the fridge to set. Before serving, take the cake out of the fridge to come to room temperature.
Nutritional information is approximate and a guideline only.