Preheat oven to 170°C fan forced. Spray and line with baking paper a 20 x 20cm square baking pan.
In a large bowl, combine the flour, baking powder, cocoa, coconut and brown sugar. Whisk together well to ensure a good mix of dry ingredients.
In a small bowl mix together the egg replacer and water, whisking for 20 seconds to remove any lumps. Add melted butter, golden syrup and vanilla, mixing well.
Add wet ingredients to the dry ingredients and mix well with a wooden spoon.
Pour mixture into prepared tray and bake in oven for 40 minutes or until brownie is cooked when tested. Allow to cool completely before cutting. Dust with icing sugar if desired.