Mix the 1/2 cup butter, white sugar, egg and cocoa. Set over boiling water and stir until mixture resembles a custard. Combine crumbs, coconut and nuts. Combine with the butter/sugar mixture, blending well. Spread and press tightly into a 9 x 9 inch pan. Cream the 1/4 cup butter, milk, custard powder and icing sugar. Spread over mixture in pan. Melt the chocolate over hot water; add butter and blend well. Spread over the icing. Let set. Chill and keep refrigerated. NOTES: * A Favorite Canadian sweet -This comes from a page in an obscure magazine called something like "Canadian Homemaker_, by way of a Canadian friend, Steve Deering. This is a traditional Canadian sweet, much loved and admired. The origin of the recipe seems to be lost in the mists of time, though everyone seems to agree that it comes from the town of Nanaimo, in British Columbia. : Difficulty: easy. : Time: 20 minutes preparation, several hours chilling. : Precision: measure the ingredients. : Barry Hayes : Stanford University, Stanford, California, USA : bhayes@glacier.stanford.edu decwrl!glacier.stanford.edu!bhayes : Copyright (C) 1986 USENET Community Trust