Preheat the oven and grease the pan. Flour the bottom of the pan. Beat cream, butter and sugar. Add eggs and mix.
Mix cocoa powder, vanilla extract and red food colour, and make a paste. Add this to the prepared batter. Mix well to get the colour. Slowly add the buttermilk and half of the flour. Mix until combined well. Add buttermilk and leftover flour. Beat at high speed to get a smooth mixture. Reduce mixing speed and add vinegar, a pinch of salt and baking soda. High the speed and mix until smooth texture appears.
Pour in the baking pan and bake (30 min). Cooling time is 10 min and, then take cakes out of the pan and let them cool properly.