Heat your oven to 350F. Spray a 8" square baking pan with vegetable cooking spray.
Place 1/2 cup granulated sugar into your food processor and pulse until fine, roughly a minute. Remove from the food processor and place in a bowl. Set aside.
Drain the fluid from one can of chickpeas into a mixing bowl. Then pour the chickpeas, along with the coconut oil, peanut butter and 1 tablespoon of vanilla extract into your food processor bowl (no need to clean any excess sugar from the previous step). Pulse until smooth.
Add the sugar and chopped chocolate to the food processor. It will be a bit bumpy, but pulse 30 seconds, up to a minute to break up the chocolate.
Add in the cocoa powder, flour, ground flax, and cornstarch and plant-based milk. Give the mixture a few more pulses until the ingredients are combined.
Pour the brownie batter into your prepared pan, using a spatula to get it all. Bake for 30 minutes.
Once the brownies are done, remove them from the oven and set aside to cool.
While the brownies are baking, make the vegan meringue. Add the Cream of Tartar to your chickpea brine. Use a mixer and mix on high until frothy.
Add one tablespoon at a time of the fine sugar (from step #2 above) as you continue to mix the chickpea brine. Continue mixing on high until soft peaks form. Add 1 teaspoon of vanilla and xanthan gum and continue mixing until stiff peaks form.
Once the brownies have baked for 30 minutes, remove from the oven and allow to cool slightly. While the brownies are sitting, turn the heat up to 375F. Spoon the meringue over the top of the brownies, creaking peaks with your spoon. Return the brownies to the oven and bake for another 10 minutes, until the meringue is set and the peaks turn golden.
You can use granulated sugar, we just prefer coconut sugar because it is a lower glycemic sweetener.