Preheat the oven to 180•C and grease two 24 cm deep cake tins with nonstick baking spray.
In a large bowl or the bowl of a stand mixer, mix the butter with the flour, caster sugar, cocoa powder and bicarbonate of soda until the mixture resembles breadcrumbs - in a stand mixer this takes 1 - 2 minutes or around 5 minutes by hand if you rub the mixture between your fingers.
Add the eggs, buttermilk, vanilla, food colouring and vinegar and mix well until thoroughly combined and smooth. The batter should be silky and bright red.
Divide the batter between the two greased tins and bake for 30-35 minutes until a skewer inserted into the centre comes away with only a few moist crumbs.
Allow the cakes to cool on a wire rack, top side down until cool to the touch. If the cakes have domed, level and cut the domes off the cakes. You can use some of these crumbs to garnish the cake later.
While the cake is cooling, make the icing. Mix together the butter and icing sugar and beat until properly combined with a stand mixer or hand held whisk- you can use a tea towel to cover the bowl to make sure the icing sugar doesn’t fly everywhere.
Beat in the cream cheese for around 5 minutes until thick, smooth and fluffy.
Use half of the cream cheese icing to sandwich the two cakes together, and then ice the top. Use any crumbs to garnish the cake and enjoy.