1. Preheat oven to 180°C, line a 22 x 30cm baking tin with baking parchment. Place the chocolate and dairy free pure sunflower spread in a heatproof bowl and set over a saucepan of barely simmering water, making sure the base of the bowl does not touch the water. Stir constantly until melted and smooth.
2. With a hand-held electric mixer, whisk the sugar and eggs together for 2-3 minutes until pale and fluffy. Slowly add the melted chocolate and Pure dairy free sunflower spread, then add the vanilla extract and continue to whisk until thickened.
3. Lastly, sift in the flour and baking powder and fold in gently. Turn the mixture into the prepared tin and bake in the middle shelf of the oven for 25 minutes until the top is firm and the cake has come away slightly from the sides of the tin.
4. While the brownie is cooling, prepare the frosting by placing the Pure dairy free sunflower spread in a stand-alone mixer. Add half of the icing sugar and mix for a minute or two to combine. Then switch off the machine and scrape down the sides with a spatula and add the salt and vanilla extract. Switch back on again and add in the rest of the sugar with the cocoa powder and mix until combined. Drizzle in enough of the rice milk to make a nice smooth frosting, scraping down the sides again with the spatula if necessary. The finished frosting should be nice and thick and spreadable. Spread the cooled brownie with the frosting and cut into squares.