Once upon a time there was a writer (who bore an uncanny resemblance to the owner of this blog) who was pulling an all-nighter in an effort to finish a book.
She started out in the morning of the day before, drinking hot tea with milk and sugar — a soothing and respectable brew, one that stiffens the sinews for the work ahead. I can’t be certain, but I think the tea was English Breakfast. .
She worked through the morning and into the afternoon, and at some point in the process she switched to coffee — no sugar, but plenty of cream — and kept on going. I don’t know what she made for dinner that night, but it was probably something simple and mindless, because her brain was deep into that writing space where the internal world has at least as much reality as the external one, and things like complex recipes are beyond it at such times.
And she kept on writing, throughout the afternoon and on into the evening.
At some time around midnight she switched to instant hot chocolate made up using strong black coffee as the liquid — a truly deadly brew, but a potent one. Fueled by several cups of the coffee-and-chocolate mix, she finished the first draft of the novel, then collapsed into bed at 4AM, weeping with exhaustion and the conviction that the book in question was utterly hopeless.
(It wasn’t. But it would take a cast-iron ego to believe that, at 4AM on a caffeine jag.)
I’m not sure that there’s a moral to this story, other than “Caffeine necessary; too much caffeine bad,” or maybe “Writers on a deadline have been known to do silly things.”
Dr. Doyle's Blog 
It probably says something about me that I discovered the trick of instant hot chocolate made with brewed coffee when I was ten.
Probably nothing very good.
I learned it from my husband/co-author, who used to be in the Navy, where they drank it on the midwatch.
That doesn’t surprise me. I devised it as a reward for shoveling snow. My grandmother had taught me to like coffee when I was two…