Whisk together the flour, sugar, baking powder, salt, mace and cinnamon in a mixing bowl.
Add the lard and butter and use your hands or a pastry blender to cut it in until it resembles coarse crumbs. Stir in the currants.
Add the egg and mix it into the batter, adding milk a little at a time, until a soft dough forms. The dough should not be wet or sticky. Wrap the dough in plastic wrap and chill in the fridge for 30 minutes.
Put the dough onto a floured surface. Use a rolling pin to roll it out to about a ¼-inch thickness. Using a drinking glass or biscuit cutter, cut the dough into rounds. Take the scraps and re-roll to cut remaining biscuits.
Heat a cast iron skillet over medium heat (you can add a tiny bit of butter to the pan, if desired). Add the cakes and cook until lightly browned on each side and cooked through, about 3 to 4 minutes. Remove to a plate, then dip the tops into granulated sugar. Enjoy hot.
