1. Preheat the oven to 350 degrees Fahrenheit and line a baking sheet with parchment paper. Set aside.
2. To prepare the “flax egg” mix together a ground flaxseed meal with the two and a half tablespoons water in a small bowl. Set aside for five minutes, until it becomes a thick gel.
3. In a medium bowl, whisk together the almond flour, sea salt, and baking soda. Set aside.
4. In a bowl of an electric stand mixer fitted with a paddle attachment (or using a handheld mixer with a bowl), combine the vegan butter, brown sugar, granulated/cane sugar and vanilla extract. Beat on medium speed three to five minutes, until combined and creamy.
5. Next, mix the flax egg and peanut butter into the butter mixture until just combined.
6. Pour the dry ingredients (from step three) into the butter-egg mixture and mix on medium speed just until combined.
7. Using a rubber spatula, fold the chocolate chunks into the cookie dough.
8. Using a 1/4 cup, scoop about nine cookie dough balls onto the parchment-lined baking sheet, leaving two inches of space between each mound of dough. If making smaller cookies (totalling 18 cookies), scoop two-tablespoonfuls per cookie.
9. Refrigerate the dough for 15 minutes (if you have the time).
10. Bake cookies for 18-20 minutes in the middle oven rack. Sprinkle cookies with flaky sea salt right after baking.
11. Allow cookies to cool on a wire baking rack for 10 minutes.