This is one of very few recipes from ToH that has truly been a disappointment. I know that the ToH test kitchen tests all recipes before publishing, but I'm truly befuddled as to how they got this one to work as written. Both direct heat and mixing with moisture-laden ingredients (such as, in this case, butter) are disasters waiting to happen when it comes to melting chocolate. Still, since I trust ToH, I first tried making this recipe exactly as it's written. Sadly, as expected, my chocolate seized up and then, as a result, the egg (even after tempering with some of the seized chocolate/butter mixture) hit the hot saucepan and immediately began to scramble. I threw it all out and started over.
This time, I relied on my own experience and melted the butter gently in the microwave, then added shortening instead of butter. I tempered the egg, then put it all in a saucepan and began to heat over low. I kept it over the heat for a good 10 minutes before I started to see a little bit of a change in the appearance and felt as though the egg had been heated sufficiently to make it safe to eat. I then followed the rest of the recipe as written.
I must say... they turned out amazingly pretty! The photo doesn't do them justice. The pastel marshmallows, once cut, really do look luminescent! I found that by letting the log rest at room temperature for about 30 minutes after it came out of the freezer, it became easier to cut and the chocolate didn't smear across the marshmallows. A serrated knife is a must! That said, no one in the family except my 6-year-old even pretended to care for the flavor of these pretty treats. You see, each color marshmallow is a different fruity flavor! We just didn't find the resulting multi-fruit flavor to blend well with the chocolate, walnuts, and coconut. I think that substituting regular white mini-marshmallows would save the taste, but then of course you'd be giving up the pretty look which led to these treats in the first place.
Overrall, even though I was able to make the recipe "work" with my own corrections, I do not consider this recipe to be a keeper.