by Gennie Truelock
I love a mystery. As a kid, I remember checking out and voraciously reading the Nancy Drew books from my elementary school library, and to this day, I have fond memories of the Sherlock Holmes unit given by my 6th grade English teacher. Instilled at a young age, that love of mystery and sleuthing has continued, which is one of the main reasons I have so enjoyed contributing to the Female Justice series of programs at the Homestead Museum. Speaking of Female Justice, I will be giving the first presentation of the 2021 series on Sunday, January 31, on the alleged 1926 kidnapping of LA-based evangelist Aimee Semple McPherson and the questions surrounding her five-week disappearance. (You can read more about her on the blog here.) But now back to this week’s mystery…
As I was preparing for this post, I was once again thumbing through the cookbook Any one can Bake, produced by the Royal Baking Powder Corporation (you can read about the history of baking powder and the Royal Baking Powder Corporation in this previous post). I was very surprised to come across a baking section titled Tropic Aroma and Other New Cakes, in which I saw they had listed the Tropic Aroma cake as the “First Mystery Cake.”
“What does that mean?” I wondered. It was time to grab my deerstalker cap and magnifying glass, because as Holmes said to his partner Dr. Watson, “The game is afoot.”

Mystery cakes
I began “The Case of the Mystery Cake” by googling the term. It turns out that there are a variety of cakes that have been given this moniker. The earliest reference I found to a “mystery cake” was from a May 1897, newspaper The Dayton Herald from Dayton, Ohio. The article talks about the retirement of a young female teacher who was leaving the profession because she was getting married.

At the party given in her honor, a “mystery cake” was served. From the description in the paper, the cake had baked inside at least three objects: a ring, a six-pence coin, and a thimble, which all held various meanings. The ring typically symbolized upcoming nuptials for the receiver, the coin was wealth, and the thimble, well, that foretold spinsterhood. This type of cake, also known as a “fortune-telling” or “divination” cake, was a popular party cake for Halloween, Christmas, and New Year gatherings. It also seems to have much in common with another objects-baked-in-dessert tradition, the King Cake, which typically has a baby Jesus, or fava bean meant to symbolize the infant, baked inside and eaten on Epiphany or Twelfth Night. The receiver of the slice containing the charm is meant to have good luck in the upcoming year, though I have heard that some families now use the charm as a way to select the host of the party for the next year.
The origin of hiding objects in desserts seems to stem from Roman and Irish traditions around celebrations of Saturnalia and Halloween respectively. In the Roman Saturnalia celebration, a ring was baked inside a galette (a free-form pie). The lucky person who ate the piece containing the ring was dubbed “king of the day.” The Celts ate a fruit-laden bread called Barmbrack on Halloween that contained objects that were meant to foretell a variety of life outcomes for the person receiving the slice: a pea (delay in marriage), stick (unhappy marriage), piece of cloth (poverty/bad luck), coin (wealth/good fortune), and a ring (married in the year).
While this is an interesting, albeit dental-work-endangering, type of cake making, it didn’t fit the description of the Tropic Aroma cake. Since the recipe made no mention of inserting objects into the batter prior to baking the cake.
So, I kept on looking.
Mystery cake, take 2: A Red Herring?
As I continued digging, I came across another type of cake referred to as a “mystery” or “secret ingredient” cake. I will tell you right off the bat that I am very glad that the Tropic Aroma cake was not this type of cake. This cake contained a pretty bizarre (in my opinion) canned ingredient. It appears to have been created around 1928 and rose in popularity during the Great Depression, it saw another peak in common usage during World War II, and was useful to home bakers when they had little butter and no eggs on hand. Any guess what it might be?

The “mystery” was that it contained tomato soup, perhaps the cinnamon and nutmeg hid the flavor?? Maybe when I am feeling a bit more daring, I’ll give the recipe a try, but if anyone who is reading this has eaten this cake before or is willing to try the recipe, I’d love to hear about it.
Since no soup of any kind was called for in the recipe for the Tropic Aroma cake, I thought that the mystery would go unsolved. However, I had a surprising discovery when I was researching another topic in the newspaper archive and saw this ad on the left-hand side of the page.

An answer appears
Was it all a marketing ploy? I began to look for references to the Royal Baking Powder company and its mystery cakes and came across other advertisements for competitions they held to develop new cake flavors using Royal baking powder as an ingredient as well as additional prizes for naming these “mystery cakes.”

Now that the mystery was solved regarding why the Tropic Aroma cake was referred to as the first mystery cake. I began to wonder, “Who came up with the recipe?” Luckily, I was able to find an answer to that question.

The Tropic Aroma cake was created in Long Beach! Even though it took digging through the newspapers of many other states, it all led me to the discovery that the cake was actually developed much closer to home. Now I had to give the recipe a try. I followed it as written and here’s how it turned out.
I don’t often make three-layer cakes but this one was pretty simple to do. I would recommend using 8-inch cake pans and baking the cake at 350˚ for about 25 minutes so that the outside doesn’t brown too quickly.
The cake is very good. The crumb is tender and moist because of the milk. You can really taste the cinnamon and nutmeg which pairs nicely with the chocolate, although I think the addition of a teaspoon of vanilla wouldn’t hurt. The frosting, although it takes 3 cups of powdered sugar, is balanced with the coffee, and because the amount made is just enough to cover the cake, you aren’t overwhelmed with a super sweet dessert. All told, I would say that it is a pretty successful recipe.
The only mystery left to solve is what am I going to do with all this leftover cake?