Pre-heat oven to 350°F with rack in the middle of the oven.
Add cider vinegar to plant-based milk (soy), stir to combine and thicken and let rest while preparing dry ingredients.
Combine all dry ingredients in a large mixing bowl.
Combine pumpkin purée and maple syrup with the soy milk mixture.
Stir wet ingredients into dry ingredients until combined ONLY once oven has pre-heated. If using organic baking powder, it is only single-acting (activated by moisture) rather than double-acting (also activated by heat). You will want to place the loaf pan in the oven as soon as you have mixed the wet and dry ingredients to avoid the bubbles escaping before the cake has started to bake!
Add the mixed batter to a parchment-lined loaf pan and place in the oven to bake straight away.
Bake for approximately 65 minutes or until an inserted wooden skewer or toothpick is removed cleanly. Add an additional 5 minutes at a time, checking with the skewer, as required.
Let cake cool completely before frosting.
Add the quarter cup of cane sugar to a high power blender and blend for about 30 seconds to produce a fine confectionary consistency sugar.
Add the maple syrup and ground cinnamon to create the desired glaze consistency. You want the glaze to flow sufficiently to drizzle over and penetrate the loaf.
Drizzle the glaze over the loaf, allowing it to penetrate.
Before serving, sprinkle some additional blended cane sugar (or icing sugar) over the top of the loaf top (optional).