Preheat oven to 350 degrees and line your baking sheet with parchment paper. Prepare your flax egg by combining 1 tablespoon of ground flax meal with 3 tablespoons of water. Let is sit for 5 minutes.
Whisk together flour, baking powder, baking soda, salt and set aside.
In the bowl of your standing mixer in medium speed, mix together your melted butter with sugars. Then add the flax egg and 3 tablespoons of aquafaba and whip until well combined. Scrape down the sides as needed and slowly add the flour mixture. Once combined, stir in chocolate chips.
Let the cookie dough rest for 15 minutes.
Using a cookie scoop or spoon, scoop out about 2 tablespoons of cookie dough onto cookie sheet. Bake for 12-16 minutes (depending on your oven, mine bakes for 16) until golden. Take the cookie sheet out of the oven and let it sit for 5 minutes before transferring to a wire rack. Let it cool before eating.
Letting the dough rest is crucial for the cookie rise. Don’t skip it!