First make your flax eggs. Grind up flax seeds or linseeds in a food processor or blender. Add the flax meal to a bowl, then add the water. Stir and pop in the fridge to thicken for 20 minutes.
Preheat the oven to 180c/160c fan/350f/gas mark 4 and line your bownie pan.
Add the chocolate and butter to a bowl and melt in the microwave or in a bain marie (bowl over a pot of simmering water, making sure the base of the bowl doesn't touch the water).
Add the sugar to a mixing bowl, then add the vanilla extract and flax eggs once they have thickened and whisk with a fork.
Pour in the melted chocolate and stir in.
Add the flour and salt, then fold in until just combined. Pour the brownie batter into the lined brownie tin and bake for 20-25 minutes.
Remove from the oven and leave to cool in the tin.
While it's cooling make the icing. Add the icing sugar to a bowl and add the water a little at a time, you probably don't need it all.
Once you have a thick icing, divide into two bowls and add a different colour gel to each (a few drops) and mix.
Test the icing on kitchen paper. Drizzle a little. If it''s too loose, add some more icing sugar. Once it's just right drizzle over the brownies.
Add the mini eggs, pushing in slightly.
Cut into 16 squares (or more) and serve.
Enjoy!