Preheat the oven to 350 degrees Fahrenheit. Line a loaf pan with parchment paper.
In a blender, add ground flax seeds, almond milk, lemon juice, applesauce, and melted vegan butter. Set aside.
In a large bowl, add almond flour, oat flour, arrowroot starch, baking soda, baking powder, ground cinnamon, salt, and organic cane sugar. Whisk to combine.
Add vanilla extract to the mixture in the blender, and blend on high until smooth. Fold liquid mixture into the dry mixture. Stir until all ingredients are moistened.
Pour half the batter into the prepared loaf pan. Combine cinnamon sugar swirl ingredients in a small bowl. Sprinkle half of cinnamon sugar mixture on top of batter. Pour remaining batter on top. Sprinkle remaining cinnamon sugar in an even layer on top. Bake for 55-60 minutes, or until a toothpick comes out clean.
Remove gluten-free cinnamon bread from oven and place on a wire cooling rack. Allow to cool completely before topping with glaze.
When ready to glaze, combine all glaze ingredients in a small bowl. For a thicker glaze, add a little more powdered sugar. For a thinner glaze, add a little more almond milk. Pour glaze over top of bread and spead into an even layer, allowing to drip down the sides.
Allow glaze to set before slicing and serving.