Erle Stanley Gardner recommends ...

From The Case of the Crooked Candle:
Cameron's eyes twinkled in quiet humor. A short, stubby pipe was gripped in his teeth firmly. He removed this pipe, said, "Better come in for a few minutes and get warm. It's going to be mighty cold out there on the water. There's a stove in the cabin of the yacht, but you'll be plenty cold getting out there. I've got a kettle of hot water on the stove and some rum. If you folks would like a hot buttered rum, I ..."  
Mason didn't even wait for him to finish. "What is holding you back?" he demanded.  
Cameron smiled and, glancing at. Della Street, asked Mason somewhat diffidently, 'Two glasses or three?"  
It was Della who answered the question. "Three," she announced.  
"And you can make 'em just as strong as you like," Mason said.  
Cameron put a generous portion of butter into three cups, adding boiling water, sugar, spices, and then poured in the rum. "Got a brother in the dairy business," he said. "Manage to keep myself supplied with enough butter to take the edge off my rum toddies. You folks want to take your coats off?"  
"No," Mason said. "We'll get started as soon as we've finished our rum, and it won't do us any harm to get good and warm before we start."  
Della and Mason silently toasted each other over the rims of the thick porcelain cups, then sipped the hot beverage. "That," Mason announced, "is a lifesaver." 
I had never had hot buttered rum in my life. Before I read this passage. I have now. It is great stuff. I lift my mug to salute Perry, Della, Cameron, Erle and Bacardi.