The recipe according to the city of Nanaimo website (http://www.nanaimo.ca/EN/main/visitors/NanaimoBars.html) is as follows:
Bottom Layer
½ cup unsalted butter (European style cultured)
¼ cup sugar
5 tbsp. cocoa
1 egg beaten
1 ¼ cups graham wafer crumbs
½ c. finely chopped almonds
1 cup coconut
Melt first 3 ingredients in top of double boiler. Add egg and stir to cook and thicken. Remove from heat. Stir in crumbs, coconut, and nuts. Press firmly into an ungreased 8" x 8" pan.
Second LayerCream butter, cream, custard powder, and icing sugar together well. Beat until light. Spread over bottom layer.
½ cup unsalted butter
2 Tbsp. and 2 Tsp. cream
2 Tbsp. vanilla custard powder
2 cups icing sugar
Third LayerMelt chocolate and butter overlow heat. Cool. Once cool, but still liquid, pour over second layer and chill in refrigerator.
4 squares semi-sweet chocolate (1 oz. each)
2 Tbsp. unsalted butter