In a saucepan boil the cider until it is reduced to about 1/4 cup and let it cool. In a bowl whisk together well the pumpkin purée, the eggs, the oil, the brown sugar, the zest, and the reduced cider. Into the bowl sift together the flour, the baking powder, the salt, the baking soda, the mace, the cinnamon, and the cloves, and stir the batter until it is just combined. Transfer the batter to the prepared loaf pan and bake for 45-60 minutes, or until a tester comes out clean. (Note: Check the bread at about 35 minutes and cover with foil for the remainder of baking time if the surface has begun to brown.) Let the bread cool in the pan before serving.