Get a clue: The secret to Mystery Cake revealed

Hey there, you. Yes, you the baker. It’s me, your New Year’s Baking Resolution. You know the one where you said you were going to be more adventurous, try new recipes, new ingredients, new flavors?

I’ve been hard at work searching for our first escapade, and have I got a doozie! Ready to learn more? Check out this Mystery Cake, it’s made with..


Oh no you don’t, get back here! You promised! Here, does this help?


Ah, now that’s better. Mystery Cake is really a spice cake, rich with cinnamon and cloves, which just happens to use tomato soup. Trust me, it does not taste like tomatoes and if I hadn’t told you, you never would have known and probably would have had two pieces, making Weight Loss Resolution rather miffed.

Actually, Weight Loss would be pretty pleased with this cake. It hails back to the 1930s, when butter and eggs were precious commodities, so very little of either were used in this recipe.

Don’t get the wrong idea, though. This isn’t a dry cake. On the contrary – it’s very moist thanks to the soup, and doesn’t even need any icing, although vanilla icing just sends it over the top of Mount Yummy. This cake was wildly popular for the better part of 40 years, until packaged mixes and flashy new recipes such as Red Velvet cake (1962) and Tunnel of Fudge (1966) pushed it out of the limelight.

NO MORE, I say! YOU are a culinary leader for a new year, a new decade!  YOU can bring Mystery Cake back to its former glory, and win the praises of your family, friends and co-workers at the same time.

YOU are a Baker!

Oh, good. I can see from that look in your eye that you’re intrigued, inspired even. Let me show you how easy it is to make this cake, and you’ll be off on the road to culinary greatness in 2010.


Preheat the oven to 350°F. Lightly spray a 9″ round cake pan with cooking spray.


Line the pan with a circle of parchment paper, and spritz again.


In the bowl of your stand mixer cream the butter and sugar until light and fluffy. The butter will lighten up in color and the sugar will blend in until it’s nearly invisible.


Add the egg and beat until the batter is smooth and well combined.


Now for the fun part. Stir the baking soda into the can of undiluted soup (10 3/4 ounce size) . Kids love this part, it’s like a science fair volcano.


Check out the fizz! Time to get this into the batter before we’re cleaning tomato soup lava from the counters.


Pour the soda/soup mix into the batter and stir to be sure all the soup is combined.


At this point the batter will look curdled. That’s normal and will be fine once the flour is mixed in. Hey, I’m your Baking Resolution. Would I steer you wrong?


Add the flour, baking powder and spices. You really should do this in a small bowl and whisk them all together first, to be sure that they are well combined. I think Less TV Resolution was out to lunch and I got caught up in a riveting episode of SpongeBob for a moment there.

Blend until well mixed. Stir in the raisins (if using).

Oooh, aren’t you the creative thinker! Yes, you can use currants, or nuts, or a combination. If it sounds good to you, go for it! Just keep it around a 1/2 cup total.


Pour the finished batter into the pan and bake for 30-35 minutes.


Doesn’t that smell great? Oh, sorry. I forgot you don’t have smell-o-screen. I think that’s on Bill Gates’ Resolution list though. Shhh, I’ve said too much!


After loosening the sides of the cake from the pan, turn it out on a rack to cool. Peel the parchment circle off and revel in the easy cleanup.


Like I said before, this cake doesn’t need any icing, but a simple vanilla glaze makes it over-the-top good. I’ve also heard that chocolate icing is delish, and cream cheese icing transforms Mystery Cake into a real celebration cake. If I may say so, it’s mmm-mmmm, good!

I, your humble New Year’s Baking Resolution, am so proud of you. You embraced the challenge with open arms and an open mind. I’m hot on the trail of our next culinary outing and I’ll check in with you soon.

By the way, how do you feel about kelp? Or escargot? Wait, come back! Come baaaaack…

Please view, bake and review our recipe for Mystery Cake.

MaryJane Robbins

MaryJane Robbins grew up in Massachusetts and moved to Vermont 20 years ago. After teaching young children for 15 years, she changed careers and joined King Arthur Flour in 2005. MaryJane began working on King Arthur Flour's baker’s hotline in 2006, and the blog team ...


  1. C.A.Zeidler

    Can you use Campbells Tomato Bisque soup? Was on sale and hubby bought a years worth! LOL I have eaten about all the chili I can stand using this bisque, cake would be a welcome relief if possible to use.

    1. The Baker's Hotline

      It’s worth a try! If it has a lot of added herbs or flavors like onion or garlic it may not be terribly enjoyable though. Maybe try a half batch first to be safe. Annabelle@KAF

  2. Mary Fowler

    My mother always made Tomato Soup Cake for my birthday; she even sent one to me each year I was in college. My roommates and friends turned green when I told them it was made with tomato soup; however, they all came back for seconds once they had tried it. She always put dates and nuts in it and frosted it with cream cheese frosting. You have inspired me to make one for my 84th birthday this year….October 29th…and perfect for Hallowe’en!.

    1. PJ Hamel

      Mary, Happy 84th – and enjoy your tomato soup cake! You and my husband share the same birthday (though you’ve got 16 years on him), so I’ll raise a slice of his pineapple upside down cake to you Oct. 29. 🙂 PJH

  3. Janie

    Tomato Soup Cake has been in our family for generations! Handed down from my grandmother, her recipe contains dates and pecans and is topped with her recipe for Cream Cheese icing! She made one for our birthdays every year and its was what we looked forward to most! My sister is baking one right now for our mom’s 88th birthday tomorrow!

  4. lmmk

    My mother made this all the time and I loved to watch the looks on my friends’ faces when I told them it was Tomato Soup Cake.

    She also made Mayonnaise Cake and Saurkraut Cake, both recipes made amazing chocolate cakes. Unfortunately, I’ve not been able to find her recipes, but I keep looking

  5. Ted

    I’m guessing the reason the baking soda goes into the tomato soup is to lower the acidity? But wouldn’t that happen is you mixed the soda in with the other dry ingredients? It would seem to be a bit simpler to do that.

    Baking soda helps to eliminate the tomatoes’ acidity, allowing their rich flavor to shine through. It’s best to follow the recipe as written and accomplish this before mixing with the other ingredients. Happy Baking – (or volcano making?)! Irene@KAF

  6. Addie

    My mom had a tomato soup cake recipe that she made in a loaf pan – it was one of my favorite recipes, but it tended to “fall” everytime we baked it – i think because it was hard to get all the heavy ingredients to bake evenly. Why we never tried baking it in a different pan, I don’t know – I know what i’m going to do now!!

    For those who are skeptical about the sound of this recipe, it’s really just a very tasty spice cake. It was a family favorite of our household from many years ago.
    Thanks for sharing Addie. Yes, you’re probably right about the cake in the loaf pan. Give it a try in a 9×9 and I bet you’d see a big difference. ~ MaryJane

  7. Moira

    Hi Mary,
    Despite your advice about tomato pulp moisture, i used it any way to make the cake and guess what? It is simply fantastic. Maybe is not the same, but we loved it at home and you can see photos it at my blog:
    Thank you for sharing this wonderful recipe.
    Regards from Portugal
    Glad to hear it worked out. Thanks for letting us know! ~ MaryJane


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