melt the butter in a saucepan. Take off from heat and mix in the sugar and cocoa powder and then gradually mix in the beaten egg. Return the saucepan to low heat and stir consistently cooking until the mixture thickens.
remove from heat and stir in the vanilla, grahamcracker crumbs, and coconut. Press the mixture evenly onto the bottom of the pan. Cover and put in freezer (or fridge) until firm.
in an electric mixer, or with a hand mixer, beat the butter until creamy. Add the remaining ingredients and beat until the mixture is smooth. If the mixture is too thick to spread, add more cream or milk. Spread mixture over firmed bottom layer, cover and freeze/refrigerate until firm.
melt the chocolate and butter in saucepan. Spread the melted mixture evenly over the firmed middle layer freeze/refrigerate until the chocolate has set.
using a sharp knife, cut into squares. I like to wait a while before cutting and eating the bars so that they are firmer and cut better.