Preheat oven to 350 degrees F. Line a large baking sheet with parchment paper or a silpat mat.
In a large bowl, make flax egg. Combine the ground flax seed and water. Mix and set aside for 5 minutes to thicken.
After 5 minutes, add the maple syrup and nut butter to the bowl with the flax egg. Stir until well mixed and smooth.
Add in the muesli, oat flour, cinnamon, and salt. Mix until well combined. Fold in the chocolate chunks.
Scoop about 2 Tbsp of dough and roll into balls. You can wet your hands a little bit if the dough is sticking to your hands. Place on cookie sheet and flatten with your hands.
Bake for 13-16 minutes or until lightly golden on the bottoms.
Cool on the cookie sheet for 10 minutes. Then transfer cookies to a cooling rack to cool completely. They will firm up more as they cool.
Enjoy! Store in an airtight container on the counter for 3 days.