Preheat the oven to 350°F (175°C) and line a loaf pan with parchment paper, letting it hang over the edges.
Boil the carrot and sweet potato cubes in water for about 25 minutes, until fork-tender.
Drain and mash the vegetables with the cold water until smooth using an immersion blender.
In a large mixing bowl, combine the vegetable puree, mashed bananas, brown sugar, eggs, and vanilla extract. Mix until well blended.
In a separate medium bowl, whisk together the flours, oats, flaxseed, baking soda, baking powder, cinnamon, and salt.
Gradually fold the dry mixture into the wet ingredients, stirring gently to avoid overmixing.
Pour the batter into the prepared loaf pan. Sprinkle the top with pumpkin seeds and oats for added texture.
Bake for 60 minutes, or until a toothpick inserted into the center comes out clean.
Allow the loaf to cool in the pan for 10 minutes, then transfer it to a wire rack to cool completely before slicing.