A plate piled with cookies shaped roughly like bananas.

Banana Cookies


This is the hill we will die on: the difference between a cookie and a muffin is water.

Bananas are 75% water. If you wanted to add just one banana in a recipe that would be 87g water. That’s much too much to just throw into a batch of cookies and end up with happy cookies. Thus we have invented the eggnana! Intense banana flavor with the binding power of an egg.



  1. Brown the butter. Cook the butter in a sauce pot until it turns a light brown color. A shallow pan will cook slower but you have to watch it more carefully so it doesn’t burn, a deeper pot will require constant stirring. We measured the water loss at 34g, leaving a final measured weight of 193g browned butter. Butter is 14% water.
  2. As the butter is cooling, add the cinnamon. This will allow the flavor to bloom.
  3. Chill the browned butter.
  4. Mash the bananas. A pastry cutter works well if you have one.
  5. Microwave the bananas 30 seconds at a time until at least 54g of liquid has evaporated from the bananas leaving a final weight of at most 146g (~4 minutes). This is ~⅓ of the water content of the bananas. Watch out for the bananas bubbling up and overflowing your bowl while you microwave them (hence pausing the microwave every 30 seconds); you may want to consider using an extra large microwave safe bowl. (You can also do this by freezing the bananas, see Notes.)
  6. Allow the banana to cool.
  7. In a separate container, mix the remaining banana flesh with the flaxseed meal. This will create an egg-like binding agent.
  8. Let the flaxseed meal and banana “eggnana” coagulate for at least 3 minutes.
  9. Chop the peanuts or pulse a few times in a food processor.
  10. Whip the cooled browned butter, sugar, until creamed. This will incorporate air and water into the butter. Use the flat beater attachment on high speed.
  11. Slowly add the “eggnana”.
  12. Measure out the flour and mix in the baking soda and salt.
  13. Decrease the speed to slow, and mix in the flour mixture.
  14. Add the chocolate chips and peanuts.
  15. Shape the cookies into 1 inch spheres. If you’re feeling fun, roll each sphere such that they are ~3 inches long and a bit more tapered on one end, and then bend slightly into a crescent banana shape.
  16. Bake at 350°F for 8 minutes.
  17. Allow to rest at least 3 minutes before serving.


You can also freeze the mashed bananas. This will rupture the cells and release most of the water. Then when the mashed bananas thaw you can pour off the listed amount of liquid.

Flaxseed meal is a common egg substitute for vegan baking. It binds with water creating a coagulated binder. In this recipe we mix the flaxseed meal with banana so that all the water in the recipe can come from the fruit.

These work well baked in almost any shape, so if you’re feeling drop cookies, or really tall ones, or fun shapes they all work pretty well.