Whisk together the egg, sugar and half of the buttermilk in a bowl. In another bowl combine together the baking soda and the rest of buttermilk. Let it sit for 5 minutes. Pour the prepared egg mixture into it and blend together. Sift the flour and nutmeg in a mixing bowl together. And then add in buttermilk mixture and melted. Finally add in cranberries and combine all the ingredients.
Grease a 22-24 cm bundt pan. Pour in the cake and bake at 175C/350F for about 35 minutes or until toothpick comes clean. Cool on a rack for 5 minutes before removing from pan. Dust the cake with some powdered sugar if desired.