Preheat oven to 350F and line two 8x8 baking pans with parchment paper.
In a large bowl mix together the gluten free flour, cocoa powder, instant coffee, and salt.
Whisk together the flaxseed and the water. Let sit for 5 minutes.
Add the coconut oil and 2oz of dark chocolate to a small pot on medium heat. Once melted and smooth, turn off heat. Add this mixture to the dry mixture along with the brown sugar, almond milk, apple cider vinegar, and flax eggs. Mix until just combined.
Divide the batter evenly in to the two 8x8 baking pans. Sprinkle on more chocolate chips if desired. Bake for 20-25 minutes or until it's just set on top. Be sure not to over-bake. Let cool completely. If you have the time, place in freezer overnight.
Mix the two pints of vanilla ice cream until soft and add on top of 1 layer of the brownie. Keep the brownie in the baking pan. Add the second brownie on top and place in fridge overnight or until completely set. Cut in to 8 or more bars and serve! Enjoy.