Preheat the oven to 350ºF. Line a baking sheet with parchment paper and set aside.
Beat together the peanut butter, syrup and flax egg until smooth and creamy. Fold in the remaining ingredients (minus chocolate chunks).
Scoop about one tablespoon of dough onto the baking sheet and gently flatten with your hands. Repeat until all dough has been used.
Press a chocolate chunk into the center of each cookie and bake for 9 - 10 minutes until the cookies are lightly golden brown. Cool on the pan for 5 minutes then transfer to a wire rack to finish cooling.
* please see substitution notes in the post above!