In a large bowl, whisk the cornmeal, flour, baking powder, baking soda, and sea salt.
In a separate bowl, whisk the buttermilk, mashed banana, coconut oil, vanilla extract, and lemon extract.
Start preheating a greased waffle iron on medium-low and pour the wet ingredients into the large bowl. Whisk to combine.
Scoop about ⅓-½ cup of batter (for a Belgian iron) in the middle of the pan and press closed. If you have a smaller waffle maker, use about ¼-⅓ cup of batter instead. The iron should not be entirely full, as the batter will spread out.
Depending on your waffle maker, it may beep when the waffle is ready. If you have a simpler model, check after about five minutes to evaluate doneness. The waffles should be a deep golden brown and slightly crispy when ready.
Gently remove the waffle from the griddle and serve right away. Top with fruit, freshly whipped cream, butter, pure maple syrup, or any sort of nut/seed butter.