Combine bananas, almond milk, peanut butter, cacao powder, and collagen, maca powder, and chia seeds if using, in a blender (I used my Vitamix). Puree until completely smooth - the mixture should be thick. Add a touch more liquid if necessary to get it to blend completely smooth.
2 frozen bananas, ⅓ cup almond milk, 2 tablespoons peanut butter, 2 tablespoons cacao powder, 2 scoops protein powder of your choice, 2 teaspoons maca powder, 1 tablespoon chia seeds