Before making the dough, make the flax egg by mixing together the ground flaxseed and water and set aside.
Next, sift together the dry ingredients including the flour, cocoa powder, baking soda, and salt in a medium mixing bowl and set aside.
Add the room temperature vegan butter, white sugar, and brown sugar to a separate mixing bowl. Then, use an electric mixer to cream the butter and sugar together until fluffy (about 1-2 minutes).
Next, add in the flax egg and peppermint extract and mix together for another 30 seconds.
Then, add in the bowl of sifted dry ingredients and mix everything together until a thick chocolate cookie dough forms.
Next, add the vegan chocolate chips & crushed peppermint to the mixing bowl and fold into the dough using a spatula.
Then, cover the bowl of cookie dough with plastic wrap and add to the fridge to chill for 30 minutes- 1 hour. The dough can also be refrigerated up to 24 hours
About 10 minutes before removing the dough from the fridge preheat the oven to 350F and line a baking tray with parchment paper. Then, use a cookie scoop to scoop out 12 evenly sized cookies (about 40-45 grams per cookie) and place them onto the baking sheet. Make sure to space the cookies at least 2 inches apart on the tray and do not flatten them as they will spread while baking. All of the cookies will not fit on one baking sheet, so I recommend baking 6 cookies at a time on one tray vs. putting two trays in the oven at the same time.
Bake for 11-13 minutes until bottoms are lightly browned and the cookies are cooked through but have slightly soft centers. The cookies will continue baking after they are removed from the oven so the centers should still be soft, but not glossy or raw, when they are removed from the oven.
Remove the cookie tray from the oven and immediately tap the tray on the counter to produce a more “wrinkly” cookie and help deflate the cookies. For round cookies, use a round cookie cutter (or large mug in my case!) that is slightly larger than the cookie and swirl the cookies around inside to form them into a round cookie. This step will only work if you do it while the cookies are still warm.
Let the cookies cool on the baking tray for at least 5 minutes as they will be soft right out of the oven. Then, place onto a wire rack to finish cooling or enjoy while still warm and gooey!