Preheat the oven to 180C.
Grease the mini loaf pans with butter, being sure to get into all of the corners.
Mix together the pumpkin, sugars, oil, water, eggs and lemon zest. Beat until combined.
In another bowl sift together the flour, baking powder, salt and spices.
Add the dry ingredients to the wet ingredients and fold in until just combined.
Spoon into each of the loaf tin sections, filling about two thirds of the way. Don't overfill or your loaves will be difficult to get out and look a bit wonky.
Bake for 20 minutes or until a skewer comes out clean. Allow to cool for a few minutes and ease out the loaves allowing them to continue cooling on a wire rack.
Rinse the tin and repeat the greasing, filling and baking. Do this until you've finished using all of the batter.
When all cool, make the icing with the icing sugar and enough of the lemon juice to make a thick paste. Drizzle or pipe over the cakes and allow to set.