Preheat the oven to 210°C and line a baking tray with baking paper.
Sift flour and baking powder into a large bowl. Rub in margarine until mixture resembles breadcrumbs. Stir in oats, sugar and sultanas. Make a well in the centre and pour in buttermilk and mix with a cutting motion with a knife. Bring dough together and place it onto a floured board and knead 3 to 4 times.
Roll or pat out dough until it is 2 cm thick. Using a 6-cm round cutter, cut out scones and place on the tray, about 1 cm apart. Re-roll once to use up dough. Brush with egg, if you wish, for a golden topping.
Bake for 15 minutes until scones are cooked and lightly browned.
While scones are baking, beat all ricotta cream ingredients together until smooth.
To serve, halve warm scones and spread with ricotta cheese or spread with your favourite jam and top with a dollop of ricotta cream.