First, make the flax egg by mixing the ground flax and water then let sit 5 minutes.
In another bowl, mix all the dry ingredients together, then add the rest of the wet ingredients (including the prepared flax egg) and mix until the ingredients are well incorporated and the dough is smooth.
Chill the dough in the fridge for 10-30 minutes,
Evenly divide the dough into 10, then roll into balls
Place the cookie dough balls on a parchment paper-lined cookie tray then flatten to about ⅓ inch thickness (note*)
Bake in oven 350F for about 13-15 or until slightly golden with a browned cookie base.
Prepare the deco ingredients while the cookie bakes.
As soon as the cookies are out of the oven, remove from cookie tray and use tweezers/ plating tongs/gloved hands to press the red M&M candy on the center of each cookie, and two pretzel antlers on the upper left and right side of the cookie. Press two mini chocolate chip "eyes" in between the M&M nose and pretzle antlers.
Let the cookies cool before enjoying!