Preheat your oven to 350°F / 175°C. Line an 8-inch/ 20cm square baking pan with two overlapping sheets of parchment paper. The sides of each piece should drape over the sides of the baking pan. 

Place the vegan butter in a large microwave-safe glass mixing bowl. Microwave the butter for 30 seconds. Stir in 2 ounces / 55g of the chocolate until the chocolate is melted. Add the cocoa powder to the bowl, followed by the hot coffee and whisk until glossy. Add the cane sugar, brown sugar, oil, and vanilla and whisk together until combined. Add the flour, salt, and baking powder and whisk again until the mixture is shiny and no flour is visible.

Place the aquafaba in a small bowl. Whisk vigorously until it’s quite foamy and light, about 1 minute.

Fold the remaining 4 ounces / 115g chocolate into the batter. Then use a spatula to gently fold the aquafaba into the batter. The batter will look a little frothy, which is fine. Pour the batter into your prepared baking dish.

Bake until there’s a crinkly layer on top of the brownies and the edges are crisping, 30 to 35 minutes. Allow the brownies to cool completely before removing from the pan. Using the overhanging parchment paper, lift the baked square out of the pan, and remove the parchment. Cut them into 16 squares.

Serve right away, or meal prep for the week by transferring the squares to a single airtight container or portioning them into individual containers. Store in the fridge for up to 4 days or in the freezer for up to 4 weeks. Allow to come to room temperature before enjoying.