Oven 180*C.
In a food processor (or by hand crush) blitz the weet-bix biscuits fairly finely,
Once the weet-bix are crushed add in the flour, brown sugar, baking powder and cocoa. Give a quick blitz to mix.
Add to a large bowl the coconut and the weet-bix mix and stir.
In a microwave bowl or jug add butter and golden syrup. Microwave on high for about 50-60 seconds or until melted. OR Can be stirred in a saucepan on stove top.
Immediately add butter and syrup mix to the weet-bix bowl. Fold into mixture making sure it's well mixed from the bottom up. It's a fairly stiff mix.
Spread and press down fairly firmly and evenly into a lined lamington tray (approx 34x24cm). Bake for 20-25 mins or until done.
Blend the 1 tablespoon of cocoa with icing sugar and vanilla with enough boiling water to mix to icing consistency. Ice slice straight away and leave to cool totally in tray.
Cut and serve.
Notes
The slice has to be cold to take out of tray or it will crack. I lift out of the tray carefully with the baking paper onto a board, then cut.The reason I don't put the coconut in the processor is that the coconut to me is small enough I don't want it smaller but there is no reason you can't add it to the processor.It's a fairly big mix halve it if need be.You can use a little less margarine but only so much before it starts to crumble.This slice freezes well in a sealed container.Coconut oil works with this recipe instead of butter or margarine.Double the baking powder to make it more cake like.I pop in some chopped walnuts for something different.