Preheat oven to 350℉. Line a 9 inch pie dish with parchment paper.
In a large bowl, whisk together the bananas and eggs. Next, add in the olive oil, syrup, vanilla and whisk until mostly smooth. Add in the oat flour, almond flour, cacao powder, baking powder, baking soda, salt, espresso powder and mix together until incorporated. Fold in 2/3 of the chopped chocolate. Transfer mixture to the pie dish, spread out evenly and top withe the remaining chocolate chunks. Bake for 35-40 minutes or until toothpick comes out clean. Let it set in the dish for 10 minutes and then transfer to a cooling rack for at least 20 minutes prior to slicing.