Wonderful! Instead of mixing the egg into the chocolate mixture, it works well to mix just a little of the warm chocolate mixture in with the egg. Whisk well, slowly adding more and more hot chocolate with the cocoa.
Then when you add the egg mixture to the hot chocolate it won't be lumpy. We made it on the stove top and it worked great. It's nice to have an after school snack with some extra protein.
I opted to make mine on the stove instead of the microwave. I also used milk chocolate instead of semi-sweet and I love the cocoa taste. I think the cocoa makes this special. I topped with whipped cream, vanilla and cocoa.