In a medium bowl, soak the flour in the vinegar water for 12 to 24 hours.
Preheat the oven to 350 degrees and grease a 9 x 9 inch baking pan.
In a large bowl, mix together the eggs, banana, ghee, maple syrup, and vanilla extract.
In a small bowl, whisk together the cocoa powder, baking powder, and salt.
Add the dry ingredients to the wet ingredients and stir to combine.
Add the soaked flour to the large bowl and stir to fully combine all the ingredients.
Pour the batter into the 9 x 9 inch pan and bake for 20 to 25 minutes, or until a toothpick inserted in the center comes out clean. Cool on a wire rack and cut into 9 squares.