In a saucepan mix together butter, sugar and the beaten egg. Cook over low heat for 5 minutes, stirring constantly, until smooth and slightly thickened.
In a large bowl mix together the graham wafer crumbs, coconut and finely chopped peanuts. Add the butter egg mixture and mix well. Press evenly into an foil or parchment lined 8-inch square pan and chill for 15 minutes.
Beat together peanut butter, butter, icing sugar, and milk until smooth. (I like to do a taste test and sometimes add a bit more peanut butter). Spread over the base. Chill for 30 minutes or until firm.
Melt chocolate and butter together in a double-boiler over hot water or in the microwave. Spread over middle layer. Chill until firm and then cut into squares.