Pastry: Grease an 8-inch loaf tin. Rub the fats into the flour and salt and then mix in enough cold water to make stiff dough Roll out the pastry and cut into five pieces, using the bottom, top and four sides of the tin as a rough guide. Press the bottom and four side pieces into the tin, pressing the overlaps to seal the pastry shell.
Preheat oven to 325°F.
Filling: Mix the raisins, currants, almonds, peel and sugar together.
Sift in the flour, all the spices and baking powder and bind them together using the brandy and almost all the egg and add enough milk to moisten.
Pack the filling into the lined tin and add the pastry lid, pinching the edges and using milk or egg to seal really well.
Lightly prick the surface with a fork and make four holes to the bottom of the tin with a skewer.
Depress the center slightly (it will rise as it cooks).
Brush the top with milk or the rest of the egg to create a glaze.
Bake 2½ to 3 hours.
Test with a skewer which should come out clean; if not, continue cooking. An uncooked cake sizzles if you listen closely! Cool in the tin and then turn onto a wire rack.