Preheat the oven 180ºC/gas mark 4.
Rinse the blackberries and remove any stalks. Place into a bowl and add 50g brown sugar, juice and rind of the oranges, cinnamon, nutmeg, and cornflour. Stir all the ingredients together and place them in a 23cm square deep oven dish.
Sieve the flour and the rest of the sugar together into a bowl. Cut the butter into small chunks, and then rub into the flour until it resembles breadcrumbs.
Add cream and one egg to the flour mixture. Stir to form a soft, sticky dough. Using a heaped tablespoon, dollop the scone mixture on top of the blackberries until roughly covered. Next, beat together the remaining egg and water, then brush all over the cobbler.
Bake for 20 minutes until the crust is golden brown. Then reduce the temperature to 160ºC/gas mark 21/2 and continue baking for
This is best eaten warm, straight out of the dish, with clotted cream.