Pre-heat your oven to 180C/160C Fan/350F/Gas Mark 4, and grease and line four 8" cake tins
To make the sponge sieve the plain flour, bicarbonate of soda and cocoa powder into a bowl
In another bowl mix together the buttermilk, eggs, cider vinegar and the vanilla extract
In a third bowl cream together the butter and the caster sugar. Then add the blue food colouring, add enough for a deep blue colour
Add the flour mixture and the buttermilk mixture to the bowl in thirds, one at a time, and mix between each addition
Separate the batter into the cake tins
Bake them for 25 minutes or until a skewer inserted in the centre comes out clean, then turn them out of the pans and leave them to cool
To make the cream cheese frosting mix together the icing sugar and butter. Then add the cream cheese and vanilla. Mix well with an electric mixer then put it in the fridge to chill
To make the meringues heat the caster sugar in the oven on 200C/400F/Gas Mark 6 for 5 minutes. To find out the weight of sugar to use, weigh your egg whites, then double the sugar weight
Whip up the egg whites with the cream of tartar until stiff peaks form
Prepare the piping bags by turning them upside down and painting stripes of red food colouring on one, and blue food colouring on the other
When the sugar is done, continue to whisk the egg whites with an electric hand mixer and add the warm sugar a spoonful at a time. When it is all mixed in, keep mixing for 5 minutes until you can rub the meringue between your fingers and cannot feel any grains
Halve the meringue and put it into the prepared piping bags. Pipe it out onto lined baking trays
Bake the meringues on 90C/200F (it’s hard to convert this into Gas Mark as it’s less than a half) for 40 minutes
Trim the edges of the sponges as needed then started to stack them, spreading the cream cheese frosting between each layer. Pipe the cream cheese frosting on top for a neat finish, then sprinkled some of the crumbs from trimming the sponges on top
Decorate the top of the cake with the meringues
Store leftovers in an airtight container in a cool place and eat within 3 days