Preheat the oven to 220˚C/200˚C fan/gas mark 7. Line a baking tray with parchment paper.
Put the butter and flour into a bowl. Rub the butter into the flour with your fingers until the mixture resembles fine crumbs.
Add the orange zest, baking powder, sugar and cranberries and mix until combined well.
Add half of the milk and stir gently, then add the remaining milk and the orange juice and bring everything together into a soft, wet dough.
Turn the dough out onto a floured work surface and sprinkle with more flour. Knead the dough for 1-2 minutes, adding more flour if it becomes too sticky. The dough should be smooth and spring back when touched.
Roll the dough out to about 2½cm thick. Cut out rounds from the dough using a floured pastry cutter. Bring the remaining dough together and roll it out to the same thickness, cutting more scones from it. Continue until all of the dough has been used, being careful not to over-work it.
Brush the beaten egg over just the top of the scones with a pastry brush or your fingers, making sure it doesn’t drip down the sides.
Bake the scones in the middle of the oven for about 15 minutes, or until golden brown and risen.
Allow to cool on a wire rack. Once cool, split the scones in half, spread with orange marmalade and butter or add a dollop of whipped cream to serve.