Preheat oven to 350 degrees F. Grease a 9" x 5" loaf pan. Cut a 9" x 5" piece of parchment paper and place in the bottom of the pan. Place the flour and spices in a bowl and whisk to combine. In a second bowl, beat the sugar and applesauce until combined. Mix in the eggs and molasses. Dissolve baking soda in the boiling water and slowly stir into the sugar mixture. Add the flour mixture to wet ingredients and stir until a smooth, not overly thick, batter forms. Pour the batter into the pan. Bake for 45 to 50 minutes, or until a toothpick inserted in the centre of the loaf pulls out clean. Cool the loaf on a baking rack for 15 minutes. Use a paring knife to loosen the loaf from the edges of the pan and then unmould. Serve warm or at room temperature. Dust with icing sugar before slicing, if desired.