Line a baking sheet with parchment paper.
Place ground flax seed and water into a small mixing bowl and stir to combine, then set aside.
Add Earth Balance, brown sugar and cane sugar and beat with a hand mixer for about 4 minutes, until creamy.
Add vanilla and flax meal mixture, then beat to combine.
Add gluten-free flour, baking powder, salt, cocoa powder and rolled oats, and beat just until all ingredients are incorporated.
Add vegan chocolate chips fold them in with a spoon until evenly distributed throughout.
Use a large cookie scoop or large spoon scoop 12 large portions of dough onto the lined baking sheet (dough will be slightly runny and each cookie should be about three inches in diameter before baking).
Chill the cookies in the refrigerator for 30 minutes.
Preheat the oven to 375 degrees F.
Bake the cookies for 15 minutes or until a toothpick inserted into the center comes out clean.
If desired, sprinkle the tops with flaky sea salt.
Allow to cool for 10 minutes on the baking sheet, then transfer to cooling racks to cool completely.
Store in an airtight container, or freeze for up to one month.