Preheat the oven to 350°F. Grease and line an 8x8 or 9x9 baking dish with parchment paper and set aside.

Mix together the flaxseed with the water to create your flax eggs. Let sit for 10 minutes to thicken.

In a saucepan, melt the butter over low-medium heat. Add in sugar slowly and whisk continuously. This step is very important as it helps melt the sugar, which will give the brownies a the flakey crackly crust on the top. Continue whisking for approx 1-2 minutes after all the sugar has dissolved.

Transfer the butter mixture over to a bowl and let cool slightly. Add in flax eggs. Then add the vanilla last.

In the same bowl, sift in the cocoa powder, gluten free flour, baking powder and salt.

Mix until just combined. Transfer over to the lined baking dish.

Bake for 10 minutes. Remove from oven and add graham crackers, marshmallows, and chocolate chunks. Put back in oven and bake for another 15 minutes. Broil for 1 minute or less to brown the top of the marshmallows, keeping a close eye on the brownies so they don't burn!

Remove from the oven and cool for about 15-20 minutes before cutting. Once the brownies are cool, cut them up and devour!