Nanaimo bars

Ingredients

• 1/2 cup (125 ml) margarine
• 1/4 cup (60 ml) sugar
• 1 egg beaten
• 1-1/3 cups (325 ml) graham crumbs
• 1 cup (225 ml) shredded coconut
• 1/2 cup (125 ml) chopped walnuts
• 1/2 cup (125 ml) margarine
• 3 Tbsp (45 ml). milk
• 2 Tbsp (30 ml). custard powder
• 2 cups (475 ml) icing sugar
• 4 squares chocolate
• 2 Tbsp (30 ml). margarine