For the Base Layer:
In a small saucepan, melt together the butter, sugar and cocoa over low heat.
Add the beaten egg and continue to cook, stirring constantly to fully cook the egg to a soft scrambled texture.
Remove from the heat and add the graham cracker crumbs, coconut and walnuts.
Mix together until well combined, then press into the bottom of a parchment paper lined 9x13 inch baking pan.
For the Raspberry Filling:
With an electric mixer, beat together the butter and powdered sugar until combined.
Beat in the raspberry preserves.
Spread evenly over the base layer. Chill in the fridge for a couple of hours before adding the chocolate ganache.
For the Chocolate Ganache:
Melt butter and chocolate together over low heat, just until the chocolate is melted, being careful not to over-heat it. Alternatively, you can melt them in the microwave 30 seconds at a time, stirring in between intervals.
Spread quickly over the chilled frosted layer. Return to the fridge until the chocolate sets.
Cut into bars and enjoy!