Melt 1/2 cup butter and 1 sq chocolate in saucepan. Blend sugar, 1 tsp vanilla,egg,crumbs,coconut,and nuts into butter-chocolate mixture. Mix well and press into ungreased baking dish or square pan. Refrigerate.
Mix 1/4 cup butter,milk,confectioner's sugar and 1 tsp vanilla. Spread over crumb mixture. Chill.
Melt 1 1/2 sq. chocolate and spread evenly over chilled filling. Chill again. Cut into tiny squares before completely firm.