Preheat the oven to 350ºF. Line an 8" or 9" square baking dish with parchment paper, and set aside.
In a food processor*, pulse the wet ingredients until smooth: banana, almond butter, egg whites, vanilla, and maple syrup.
Add the dry ingredients, and continue to pulse until combined: almond flour, collagen, cinnamon, nutmeg, and sea salt.
Add the chopped nuts, pulsing just a couple of times to mix them in.
Transfer the batter to the lined baking dish, smoothing over the top. Bake for about 20 minutes, or until firm.
Allow the bars to cool, then slice into squares & serve. Store leftovers in the refrigerator. Enjoy!