Kiwi-style, Nanaimo-style, Canberra bars

Nanaimo is a city on Vancouver Island in Canada. I haven't actually been there, but I have heard of its iconic dessert, Nanaimo bars ... hasn't everyone? My favourite Canadian sitcom Corner Gas mentions them in one episode but of course calls them Nanaimo-style Saskatchewan bars, as you can't call them Nanaimo bars unless they're from Nanaimo. So, here goes. I found a recipe for Nainoma Bar [sic] in my favourite Kiwi cookbook so had a go at making them yesterday. I halved the amount of sugar in the middle (custard cream) layer and think that was a good decision; they're definitely sweet enough, even with the reduced sugar.

Base layer

125 g butter
3 tablespoons cocoa
1 egg, beaten
1 teaspoon vanilla essence
2 cups crushed malt biscuits (or similar)
1 cup shredded coconut

Melt butter and cocoa together over low heat. Remove from heat. Add beaten egg then other ingredients. Press into a high-sided baking tin. Refrigerate for 30 minutes.

Middle layer

60 g butter
2 tablespoons custard powder
1 cup icing sugar
1 tablespoon warm water

Cream all ingredients together and spread over base. Return to fridge.

Top layer

60 g cooking chocolate
1 tablespoon butter

Melt together, mix well and spread over cake. Refrigerate until firm then cut into bars or squares.