In a bowl sieve in flour, salt and baking powder. Rub in the butter until you have a breadcrumb consistency then add the chilled water 1 TBSP at a time until you have a nice dough. Press dough into a disk, cover in clingfilm and chill in the fridge while you prepare the filling.
Melt the butter then stir in the sugar, nutmeg and currants.
Roll the dough out until 5mm thick. Cut out a disk approximately 8cm in diameter.
Place 1 tbsp of the mixture in the middle of the disk and fold in the edges so the mixture is covered. Flip over so the seal is facing the surface then roll until the currants are beginning to show through the pastry. Place on a lined baking tray.
Once all of the pastry has been used, brush all the cakes with beaten egg then bake for 10-15 at 200°c until golden.