Preheat oven to 350 degrees Fahrenheit and line a baking sheet with parchment paper.
In a small bowl combine ground flaxseed (or egg replacer) and water. Let sit for 2-5 minutes before adding to recipe.
In a medium bowl combine gluten free flour, instant espresso powder, baking soda, and salt and whisk to combine.
In a large bowl beat sugars, softened butter, and flax egg until fluffy.
Add dry ingredients to wet a little at a time and mix until combined. Fold in vegan chocolate chips. Cover dough with plastic wrap and place in the fridge for 10-30 minutes to firm up.
Form dough into 1" balls and place about 2" apart on the baking sheet. Bake for 10-12 minutes, until edges are golden brown. The middle of the cookies will still be soft.
Remove from oven and let cool on baking sheet for 5 minutes before transferring to a wire rack to cool completely. Repeat for remaining dough.
Store leftover cookies (if there are any) in an airtight container for up to 4 days.
*I like to use either a flax egg (1 tbsp finely ground flax meal + 3 tbsp water) OR Bob's Red Mill Gluten Free/Vegan Egg Replacer. For the Flax Egg: Combine 1 tbsp ground flax with 3 tbsp water in a small bowl and let sit for 5 minutes before adding to the recipe. If using Bob's Red Mill Egg Replacer: Combine 1 tbsp of the replacer with 2 tbsp water, mix well, and let sit for 2 minutes before adding to the recipe. While I did not try a regular egg in this recipe, I'm sure you could use 1 egg instead of an egg substitute if you don't need a vegan (egg free) cookie.