Blend milk and vanilla pudding packets for about 2 minutes. Stir in Nutella until evenly combined. Fold in Cool Whip.
In a 9x13 pan, Layer graham crackers to cover entire bottom of pan. You may need to cut and shape the crackers to fit nicely.
Poor half of pudding/Nutella/cool whip mixture on top and level.
Arrange half of the sliced strawberries to cover entirely over the pudding mixture.
Put another layer of graham crackers to cover entire surface. Cut and shape crackers accordingly.
Put the second half of pudding/cool whip mixture on top and level.
Arrange second half of the sliced strawberries to cover entirely over the pudding mixture.
Put the final layer of graham crackers on top with bumpy side down. This will help the top look more smooth when you go to put the frosting on top. Once again, cut and shape crackers accordingly to avoid pits and cracks.
FOR THE FROSTING: Microwave butter and milk just enough so that they are melted together. You do not need to boil it. Add cocoa, Nutella and powdered sugar and blend together. This will be a runnier frosting/glaze. Pour over top of graham crackers and smooth out nicely.