Preheat oven to 350 degrees F. Line a baking sheet with a silicone mat.
In a medium bowl, make the flax egg by combining the ground flaxseed and water. Stir and set aside to thicken for 5 minutes.
In a large bowl, add the oats, baking powder, baking soda, cinnamon, cloves, nutmeg, ginger, and salt. Whisk to combine.
In the bowl with the flax egg, add the vanilla, melted coconut oil, and pure maple syrup. Whisk until well combined.
Add the wet to the dry. Stir with a spatula until combined. Fold in chopped walnuts. Use a cookie scoop (mine was 1.5 Tbsp) and scoop dough onto the baking sheet. Flatten tops slightly and bake for 13-15 minutes. Let it cool on the pan for 10 minutes. Transfer to a wire rack to cool completely. Enjoy!