Preheat the oven to 350F or 180C. Line your springform pan (or cake pan) with parchment paper and set it aside.
In a bowl, melt the chocolate and the butter together. You can use a double-boiler or a microwave.
In a separate bowl, add the water from a can of chickpeas (aquafaba) and the sugar. Mix with a hand mixer for 5 minutes till you get a foamy, thickish liquid.
Add the meltedchocolate to the bowl with the aquafaba sugar mixture. Mix with your hand mixer for 1 minute to incorporate the chocolate.
Add the flour to the mix, sifting it first for best results. Mix with your hand mixer for another minute till the flour is fully incorporated. Important: do not over-mix!
Transfer the batter into the springform pan and bake in the oven for 30minutes at 350F or 180C.
Let cool down for 10 minutes before opening your springform pan. Then serve either warm or at room temperature. Ice cream and whipped cream (plant-based if possible) are great with this vegan chocolate brownie cake.
For more comprehensive step by step instructions see "how to make chocolate brownie cake" chapter above.