For 1st Layer: Place butter, sugar and cocoa powder in double boiler over barely simmering water. Stir occasionally till melted. Add egg and stir to cook and thicken. Remove from heat and stir in graham wafer crumbs, coconut and almonds. Press firmly in ungreased 8" square pan. Chill.
For 2nd layer: Cream together butter, cream and custard powder together in bowl. Gradually beat in icing sugar till light and fluffy. Spread over first layer. Chill. For Icing: melt chocolate and butter in top of double boiler over barely simmering water (or in microwave). Stir to combine. Cool to room temp. Spread evenly over 2nd layer with spatula. Chill. Cut into bars. Makes: 16-24