Mash the bananas in a bowl. To the mashed bananas, mix the butter and jaggery powder till everything is completely blended. I prefer to mix by hand since I don't use electric mixer.
Add in the egg and vanilla extract to the above and again mix everything together using a manual hand whisk. The wet ingredients mixture is now ready.
For the dry ingredients, mix in whole wheat flour, baking soda, baking powder, ground cinnamon, ground nutmeg and salt to the wet mixture.
Finally give everything a good mix using a manual hand whisk, but do not over-mix at this stage. It is advisable to put the dough in the fridge for at least 20-30 minutes.
Remove the cookie dough from the refrigerator. Line a baking tray with parchment paper.
Preheat oven to 375 degree F.
Drop around 1 - 1 1/2 tablespoon of cookie batter/dough (using a cookie/ice-cream scoop, or using a regular measuring spoon) on parchment paper. I was able to make 19 cookies with the prepared dough (I baked these in 2 batches).
Bake the cookies for around 15 minutes in the preheated oven, or till you see creases on top of the cookies. The cookies will be soft to touch, but once cooled, they will be fine.
Remove the cookies from the oven, and allow them to cool for at least 5-10 minutes.
The Soft & Healthy Whole Wheat Banana Bread Cookies are now ready to be served. Also, these can be stored in an air-tight container for 3-4 days.