For the base, stir together softened butter, icing sugar, cocoa, vanilla, and eggs until well blended.

Add graham wafer crumbs, coconut, and nuts; mix well.

Press the mixture firmly into a 13x9 inch pan.

For the filling, cream softened butter in a medium bowl.

Mix in instant vanilla pudding powder.

Beat until combined.

Alternately beat in icing sugar and milk until smooth and creamy.

Beat in green food coloring until a mint green color is achieved.

Spread the filling evenly over the prepared base.

Chill the base and filling for 15 minutes.

Melt mint chocolate chips and milk over low heat, stirring constantly until smooth.

Spread the melted chocolate quickly over the chilled filling.

Chill the entire dessert for 2 hours before serving.

Cut into bars.

Store in a covered container in the refrigerator.