Preheat your oven to 350F and line a 12-cup muffin tin with liners.
In a large bowl, mash the 3 ripe bananas well with a fork. Add the tahini, eggs, maple syrup, vanilla extract, and vegetable oil, then mix until smooth and well combined.
3 ripe bananas, 2 large eggs, ½ cup tahini, ¼ cup maple syrup, 1 teaspoon vanilla extract, 2 tablespoon vegetable oil
Add the almond flour, protein powder, baking soda, and salt to the bowl. Mix until just combined, then fold in the chocolate chips or walnuts if using.
1 cup fine almond flour, ¼ cup unsweetened protein powder, 1 teaspoon baking soda, ¼ teaspoon salt, ½ cup chocolate chips or chopped walnuts
Divide the batter evenly among the 12 lined cups. Bake for 21-24 minutes, until a toothpick inserted in the center comes out mostly clean. A little gooey is totally fine since they'll continue to cook as they cool.
Notes
For chocolate version, add ½ cup unsweetened cocoa powder after adding the dry ingredients.