Preheat the oven to 400 degrees F and line one baking sheet with parchment paper.
In a small bowl, combine the ground flaxseed and water. Set aside for at least five minutes while you gather your other ingredients.
In a large mixing bowl, combine the solid coconut oil, cane sugar, brown sugar, and vanilla. Using a hand mixer or stand mixer, start on low speed and work to medium until combined.
Add the flaxseed water mixture and beat until just combined.
Remove the bowl from the stand mixer or remove the beaters from the bowl. The balance of the recipe will be combined with a wooden spoon.
In another medium bowl, combine the flour, baking soda, baking powder, and salt. Stir all the dry ingredients together to combine them evenly.
Add the combined dry ingredients to the wet ingredients and, using a wooden spoon, stir to combine.
Add the dark chocolate chunks and fold them to combine.
Using an ice cream scoop, scoop out 6-7 scoops of the cookie dough and place them evenly onto the parchment-lined baking sheet.
Bake in the preheated oven for about 10-12 minutes, or until the cookies are golden brown and set around the edges. They will be spread out a lot, making them extra-large.