Preheat your oven to 350F and line an 8" x 8" baking dish with parchment paper, to prevent sticking. In a small bowl, stir together the tablespoon of ground flax seed with 3 tablespoons of water, and allow to sit for 10 minutes, until gelled together.
In the meantime, whisk together the dry ingredients in a medium mixing bowl, including the buckwheat flour, spices, baking soda and salt. Add the gelled flax mixture to the dry ingredients, and stir in the melted coconut oil, zucchini puree, blackstrap molasses, maple syrup and vanilla extract. Mix well until a uniform batter is formed.
Transfer the batter to the lined baking dish, and smooth the top with a spatula. Bake at 350F for 25-30 minutes, or until the top begins to crack and the center is firm.
Allow to cool completely, then slice into bars and serve! Feel free to top with a sprinkle of coconut sugar, for presentation, if desired.
You may choose to leave the skin of the zucchini on or off, depending on how you want the final baked goods to appear. I chose to leave the skin on, for added nutrition, but there were a few green specks visible in the final result. If you want to be really sneaky, feel free to peel the zucchini first!