Changing a vegan cookie recipe? I am tyring to cut refined sugar from my diet and I have Celiac disease so no gluten is a must. Both of these things make baking a challenge. I have been using a mixture of coconut palm sugar and pure maple syrup and am liking both the flavor and the results.  

So, I find a pumpkin oatmeal cookie recipe and get to making it before I realize it has no eggs.  The resulting cookie is okay, not bad really, but not "cookie texture" to say the least.  I want to add an egg next time to add structure and chewiness but since the batter is already quite wet, what should I add (more flour? more oats?) so that the cookie dough isn't a gummy mess?

1 cup quick cooking (GF) oats,
3/4 cup flour (GF),
1/4 tsp sea salt,
1 tsp cinnamon,
1/4 tsp nutmeg,
1/4 tsp ginger,
1-1/2 tsp baking powder,
3/4 cup pumpkin puree,
1/2 cup maple syrup,
3 Tbs coconut oil (melted and cooled),
1 tsp vanilla

Mix dry ingredients and wet ingredients separately, then stir to combine.
Bake on in a pre-heated, 350 degree oven for 11-15 minutes.  Use parchment paper to avoid cookies sticking to the pan.

NOTE: I do not need exact measurements to try - I have baked all my life.  Just an idea of what to increase, add or subtract.
There are a couple of things in that recipe that appear to be used as an egg replacement:


Pumpkin puree - usual rule (as far as I'm aware) is to use 1/4 cup per egg. This is particularly good for adding moisture, so reducing this would be a good start. Baking powder can also be used in conjunction with this to leaven the mixture.
Coconut oil can also used as an egg substitute in the right context. Honey (or, as this is a vegan recipe, maple syrup) can also be used in conjunction with this, as can baking powder. However, baking powder and to a lesser extent, honey/maple syrup could still appear in a recipe before the egg has been substituted.


All in all, my suggestion would be to first reduce the amount of pumpkin puree (or possibly even remove the pumpkin puree entirely).

An alternative (although possibly a less effective one) to this, or if removing the pumpkin puree doesn't manage the job, would be to cut down on the amount of coconut oil. As you've mentioned that you like maple syrup, cutting down on that would be the last resort.

There is a question of whether the baking powder is also used to help with the lack of eggs, but baking powder often appears in recipes with eggs as well, so qualifying whether or not to get rid of baking powder is more likely to be dependent on the flour (self raising or not) used.