Preheat the oven to 325F and line a loaf pan size of 9x5” with parchment paper to prevent the zucchini gingerbread from sticking to the loaf pan after baking.
Whisk all the dry ingredients into a large mixing bowl, including the sweeteners.
In a smaller bowl, combine all the wet ingredients except the grated zucchini.
Pour the wet ingredients into the dry ingredients and mix them with a wooden spoon.
Fold in the grated zucchini and stir until all the ingredients are incorporated. The batter will be thick.
Add dollops of the batter into the loaf pan, then level it evenly with a spatula.
Transfer the loaf pan to the preheated oven and bake for 50 minutes.
After 50 minutes, poke a toothpick into the middle of the zucchini gingerbread to check for doneness; it should come out clean.
Switch the oven temperature off and leave the pan in the oven for 10 more minutes to let the center bake without burning the crust. Remove the pan from the oven and let the gingerbread cool in the pan completely before icing it.