n To prepare the cake:n Preheat your oven to 170C/340F (fan-forced). Grease two cake springform pans (6 inch) and line with baking paper.n Beat the butter with the sugar in a large bowl, until fluffy. Add the eggs one by one, beating after every egg.n Add the buttermilk, orange juice and zest and mix well.n In another bowl mix the flour with the baking powder. Add the flour to the butter-egg-orange mixture and gently fold with a rubber spatula.n Distribute evenly the batter into the cake pans.n Bake for about 40 minutes.n NOTE: If you don’t have two baking pans in the same size, bake the batter into one baking pan but pick a larger one because the batter will be too much for a 6 inch cake springform and it may not bake evenly.n If you use one baking pan, bake the batter extra 10-15 minutes (50-55 minutes total) on 160C/320F (fan-forced) or 175C/345F without a fan, let it cool completely on a wire rack and then cut it into two layers.nn To prepare the frosting:n Beat the cream in a large bowl until stiff peaks form. Add the cream cheese and melted (but chilled) chocolate and mix with a rubber spatula gently.nn To assemble the cake:n Place one of the layers on a cake stand, spread half of the chocolate frosting on top, top with the second layer and spread the remaining frosting over the top.n Store the cake outside of the fridge, covered in plastic wrap.n