The day before you make your brownies, place the carton of coconut cream in the fridge and leave for 24 hours to thicken up.
Preheat the oven to 180°C/350°F/gas 4. Lightly grease a 23cm square brownie tin with sunflower oil and line with baking paper.
In a bowl, combine the ground flaxseed with 9 tablespoons of water, stir well and leave to one side to thicken up. (The flaxseed will absorb all of the liquid, acting as a binder for the brownies.)
Drain and rinse the beans, then put in a food processor and blitz to a smooth paste. Add the flaxseed mixture, sunflower oil, sugar, cocoa, ground almonds, baking powder and vanilla extract, then pulse everything again until you have a rich and glossy batter.
Roughly chop the dark chocolate into small chunks, add to the mixture and pulse briefly just to incorporate the chocolate.
Spoon the batter into the prepared brownie tin and bake for 55 to 60 minutes, covering the brownies loosely in tin foil halfway through cooking to stop them catching. Remove from the oven and set aside to cool just a little.
In a bowl, whisk the chilled coconut cream, icing sugar and vanilla extract until thick and creamy. Slice the brownie into squares and serve with the coconut whip for drizzling.