Heat oven to 180C/160C fan/gas 4.
Grease and line the bases of 2 x 20cm
sandwich tins with baking parchment.
Using an electric hand whisk, beat
together the caster sugar and butter until
light and fluffy. Add the eggs one at a
time, beating well between each addition.
Sieve the flour and cocoa powder
into a bowl. Add half to the egg mixture
and fold in carefully. Mix together the
buttermilk, vinegar, cream cheese,
raspberry purée and food gel. Fold half
the buttermilk mixture into the cake
batter and repeat the process with both
the flour mixture and buttermilk mixture.
Spoon the combined mixtures into
your prepared tins and cook for about
25-30 mins, until an inserted skewer
comes out clean. Leave to cool for 10 mins
before turning out onto a wire rack.
For the frosting, mix together the icing
sugar and butter until soft and creamy,
then stir in the cream cheese. Sandwich
the cooled cakes together with half of the
frosting, adding 150g fresh raspberries if
you like, then spread the remaining
frosting over the top. Will keep for up
to 3 days in a cool place.