Nanimo is a place on Vancouver Island in Canada. I spent several years living on Vancouver Island when I was growing up and I very much enjoyed eating this slice from time to time.
Kiwis will be pretty familiar with this type of slice, as its very similar to our mint slice, in fact you can use this exact recipe to make it, by taking out the custard powder and adding some peppermint essence and green food colouring to the icing.
I made the one pictured in a 22cm square slice tin. I find the buttercream icing to be rather sweet, so I prefer the layers to be a bit thinner than what it might have been traditionally. If you don't have one that size, whatever you have will work, the layers will just be different thicknesses.
In Canada you would traditionally use graham crackers in the crumb, which are very similar to digestives. I got a bit creative and used Krispies, as the coconut in them lends itself to the flavour of this slice but you could also use superwines or arrowroot biscuits. It would also be more traditional to have egg in the base and bake it, but alas - I cannot be faffed with that!
Base
250g Krispies biscuits, crushed (or plain digestives, superwines or arrowroots)
1/4 tsp salt
1 cup desiccated coconut
2 Tbsp cocoa powder
195g butter, melted
Icing
120g butter, at room temp
2 Tbsp custard powder
2 cups icing sugar
2 tsp vanilla extract
3-4 Tbsp milk
Topping
180g dark chocolate
2 Tbsp coconut oil or vegetable oil Line a square baking tin with baking paper.
Use a food processor or your hands to crush the biscuits into a crumb. Place in a large bowl with salt and coconut.
Place cocoa and butter in a small pot on low heat and melt together. Once melted, pour into bowl with biscuits and mix to combine.
Transfer mixture to prepared tin and press down using a heavy glass, to really compress. Place in fridge while you make the icing.
Place all icing ingredients in a large bowl or bowl of your stand mixer and use electric beaters to beat for about 5 minutes, until fluffy and smooth. I take this one step further (if using a stand mixer) and beat on low for a further 10 minutes. This creates a very light and voluminous buttercream.
Spread the icing over the base layer, as evenly as possible. Return to fridge for at least one hour before adding the chocolate (I'll sometimes cheat this step by putting it in the freezer for 20 minutes).
Place chocolate and oil in a heat-proof bowl and melt in the microwave in short bursts, or over a pot of simmering water.
Pour the chocolate over the slice and work very quickly to spread out, then return to fridge for an hour or so to set completely.
Run your knife under hot water and wipe between slices to get a beautiful clean cut.
Store in the fridge.
