Preheat oven to 175°C (350F) and line a 9x5" loaf pan with parchment paper. Mash 3 bananas using a fork or potato masher. Set aside.
In a large bowl, sift and mix flour, baking powder, baking soda, ground cinnamon, and salt. Set aside.
Place almond butter and sugar in a large bowl of a stand mixer fitted with the paddle attachment (you can also use a handheld mixer). Mix on medium speed until well-combined. Scrape any ingredients from the side of the bowl using a spatula.
Add mashed bananas and mix well. Add vanilla extract and eggs, one by one, and mix for 1-2 minutes after each addition. Add Greek yogurt and mix until combined.
Add the dry ingredients in two additions and mix until just combined. Do not overmix. Fold in chocolate chips using a spatula.
Pour batter into prepare loaf pan, place 2 banana halves (sliced lengthwise) on top and sprinkle with brown sugar.
Cover and bake for 20 minutes, then uncover and bake for another 30-40 minutes or until a skewer inserted into the center comes out clean.
Allow to cool on wire rack, slice, and serve or store for later.