Cream the butter and jaggery powder till the jaggery powder is completely blended with the butter, do this for almost 3-4 minutes using hand whisk (If you are using electric hand mixer or a stand mixer, you can do this process on medium speed for around 2 minutes).
Add in the egg, lemon juice and vanilla extract and again mix everything using hand whisk for 3-4 minutes (For electric hand mixer or stand mixer, do it at medium speed for 2 minutes).
Add in whole wheat flour, oats flour, baking soda, salt and cinnamon to the wet mixture and mix everything together carefully for around 1 minute using hand or hand whisk (For electric hand mixer or stand mixer, do it on low speed for around 45 seconds).
Finally add the chocolate chips and chopped walnuts and mix them evenly in the dough, don't over-mix at this stage.Line a baking tray with parchment paper. Preheat oven to 300 degree F.
Take around 2-3 tbsp of dough in your hands, form a ball and place on the baking tray. Flatten the balls a little if you want thinner cookies (Highly recommended, I didn't flatten them but flattening would give you better results). Repeat this step for all the cookies. I was able to make 10 cookies with the dough as I took close to 3 tbsp dough for each cookie. You can even make a little smaller sized cookies, the number of cookies will increase then.
Bake the cookies for around 20-25 minutes in the preheated oven until edges are golden brown and center is still soft (I would recommend to start checking for doneness at 20 minutes).
Remove the cookies from the oven, and allow them to cool for at least an hour.
The Healthier DoubleTree Chocolate Chip Cookies are now ready to be served. Also, these can be stored in an air-tight container.