Place the whipping cream into the bowl of a stand alone mixer, and using the whisk attachment, whisk the cream until it has separated. Be sure to cover the top of the bowl with cling film to avoid mess from the milk solids. Remove contents to a strainer over a bowl. Cover and allow to drain well overnight to separate (in the fridge). You will end up with butter in the strainer and buttermilk in the bowl.
Preheat oven to 220 degrees celsius (200 degrees fan forced).
Using a food processor, process 100 grams of the butter made from the separation with the flour and baking powder to a fine crumb. Remove to a large mixing bowl and mix in 280 ml of buttermilk, chopped chives and salt. Mix until just combined and fold in the feta.
Tip dough onto a lightly floured surface and press together until dough is approx 3cm thick. Cut rounds using a 6cm flour dusted scone cutter. Place close together on a lined baking tray. Sqaush the remaining dough toegtehr and cut agin, repeating until all the dough is used.
Brush the top of each scone with some of the leftoevr buttermilk and bake for 13-15 minutes, until golden and cooked through. Serve warm spread with some of the freshly made butter.