Preheat the oven at 180C (356F)
In a small sauce pan, melt the vegan butter on the low heat. Set aside.
Add the vegan dark chocolate in a small bowl and place over a bigger bowl filled with 1/3 boiling hot water and stir to melt completely smooth. Set aside. Be careful not to burn yourself with the hot water!
In a large bowl, add the plain flour, rice flour, cocoa powder, sugar, and tapioca flour and mix well with a whisker.
Add in the melted vegan butter, vegan dark chocolate, soy milk and vanilla extract and fold together well the wet and dry ingredients with a large wooden spoon.
Pour the batter into the square tin and bake for 25mins. I baked this for several times in one day and 25mins gives the perfect outer crust on top and moist centre.
Take it out of the oven, let cool to room temperature, take it out of the tin, then let cool completely before cutting it into brownie squares.
Share with your friends, family, if you can resist to eat them all yourself. Enjoy!