Line a 9x9 in. baking tray with parchment paper and rub with coconut oil to avoid the batter from sticking. Preheat oven to 350 degrees F

In a large bowl, mash the bananas until they are smooth. Add the almond butter and mix until it is combined with the bananas. Sift in the dark chocolate, and add the sugar and the vanilla and keep mixing until a smooth batter forms. If you want to add anything extra such as nuts or chocolate chips, you can add them now and mix

Pour the batter into the pan and level it so it bakes evenly. Place in middle rack of the oven and bake until it is set, and the top has darkened, about 20-25 minutes

Let it cool completely before cutting and serving it