Preheat your oven to 350°F (175°C) and grease a 9x5-inch loaf pan, or line your pan with baking paper, or parchment paper.
In a medium-sized mixing bowl, with a wire whisk or fork, mix together both flours, sugar, baking powder, baking soda, pumpkin pie spice or cinnamon, and salt.
Mash the bananas in a large mixin bowl using a fork or potato masher until mostly smooth but still a little chunky.
Into the bananas, stir the plant milk, flax seeds , lemon juice or vinegar, oil, and vanilla. Mix well.
Add the dry ingredients to the wet in the large bowl. Mix with a wooden spoon or rubber spatula until just combined. Do not use an electric mixer since this will result in overmixing and a tough texture.
Fold in any additional ingredients like nuts or chocolate chips with a rubber spatula.
Pour the batter into the prepared loaf pan and smooth the top. Sprinkle the extra 2 tablespoons of brown sugar evenly over the top.
Bake for 45-50 minutes, or until a toothpick inserted in the center comes out clean.
Let it cool in the pan for 15 minutes before removing. Then let it cool completely on a wire rack.