Preheat oven to 190 C. Lightly grease the Lekue cake moulds and set aside on a single baking tray.
In a large bowl, combine the flour, bicarbonate or soda and sugars.
Combine water, cocoa powder and butter together in a medium sized saucepan and heat until melted. Do not allow to boil.
Mix vinegar and vanilla with the single cream.
Beat chocolate mixture, cream mixture and beaten eggs into the dry ingredients until well combined.
Fold in the white chocolate chips and spoon the mixture into each cake mould until each is 2/3 full.
Bake on a single tray in the centre of the oven for 30-35 minutes and then remove the smallest top tier. Return the rest of the cakes to the oven and bake for a further 10 minutes, or until a skewer inserted comes out clean.
Leave the cakes in their moulds until cold and then frost.
For the Chocolate Frosting
Beat softened butter, icing sugar, milk and cocoa powder together until the frosting reaches the desired consistency.
Leftover frosting can be frozen for later use. Alternatively, if you still have chocolate cake left a few days later you can whizz it up into crumbs and combine with enough chocolate frosting to stick the crumbs together. Dip in melted chocolate and decorate with sprinkles to make cake pops!
Mum of three, daydream adventurer, OU Life Sciences graduate, occasional crafter, ex-pat Canadian & quite possibly Britain's most northerly food blogger.