The World's Best Chocolate Oatmeal Cake Recipe - Pinch of Yum
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The World’s Best Chocolate Oatmeal Cake

34 reviews / 4.6 average

Why do people love free food?

It’s so embarrassingly true. It doesn’t matter if it’s last year’s leftover Halloween candy rejects or stale crackers from yesterday’s meeting. It’s like a science – people walk into the lunchroom, cafeteria, or whatever else you call an eating place at work and start scanning to see if there are any freebies on the counter. And if you want some, you’d better get moving. They will be gone in twenty seconds. Ten seconds. Five. Gone.

Chocolate drizzle over a cake.

Speaking as a teacher, I think that we, as a profession, are probably worst at treat hoarding. We exhaust our patience and sanity working with crazy sweet little people all day, and then we open the door into the teacher’s lounge and BAM. There they are. The treats. And with all reasonableness left somewhere between the behavior charts and excessive pencil sharpening and nose picking, suddenly we’re up to our elbows in some snack mix that we don’t even really like.

We = me.

Chocolate oatmeal cake with fudge frosting in a tin.

At my old school in Minnesota, we had a weekly treat day. Treats could be anything from a Panera bagels and cream cheese smorgasbord to a taco bar to my personal favorite – a treasure box of assorted donuts from Cub Foods. OMG. I love donuts.

One time, this cake mysteriously appeared on the counter in our teacher’s lounge. Like, this very cake that you see here today. Luckily I had the sense to snarf down an extra large piece (or two?) before the first bell and it only took one bite before I realized that this was indeed The World’s Best Chocolate Oatmeal Cake. It just happens to have oatmeal in it. Yes, that feels random to me too. Anyways, I was deliriously happy. Some fellow teachers weren’t so lucky.

One piece of chocolate oatmeal cake on a white plate with a fork.

That cake was gone before 8am, and here’s the thing: our school isn’t that big. I’m telling you. We are treat hoarders.

The baker of this thing of pure beauty turned out to be my coworker, Mimi, and better yet, her grandma turned out to be the holder of the original recipe. So. Mimi and her grandma. They ROCK.

Chocolate oatmeal cake on a fork and on a plate.

The cake is amazing. Lightly chocolatey, super moist, studded with chocolate chips, and topped with an old fashioned chocolate marshmallow frosting. The kind that crystallizes and gets little cracks in it when you slice into it. LOVE.

Chocolate oatmeal cake on a plate and a fork.

I don’t even have anything to say about the oats. It’s a delicious mystery. If that’s not your thing, this Double Chocolate Cake might be the ticket.

I see this tablescape in your future. Very soon.

Chocolate oatmeal cake slice on a white plate.
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A picture of The World’s Best Chocolate Oatmeal Cake

The World’s Best Chocolate Oatmeal Cake


This world’s best chocolate oatmeal cake recipe is from my coworker’s grandma. Made with chocolate chips, cocoa, and oatmeal, topped with fudge frosting.


  • 1 cup brown sugar
  • 1 cup white sugar
  • 1/2 cup butter, melted
  • 2 eggs, lightly beaten with fork
  • 1 3/4 cups flour
  • 1 teaspoon baking soda
  • 1/2 teaspoon salt
  • 1 1/2 tablespoons unsweetened cocoa powder
  • 1 cup quick cooking oats*
  • 1 3/4 cups boiling water
  • 1 12 oz bag chocolate chips, divided (go for the Ghirardelli*)
  • 6 tablespoons butter
  • 6 tablespoons milk
  • 1 1/2 cups sugar
  • 1/23/4 cup chocolate chips (Ghirardelli again, please)
  • 1/23/4 cup mini marshmallows*


  1. Preheat oven to 350. With an electric mixer, cream the butter and sugars. Add the eggs and mix well.
  2. Add flour, soda, salt and cocoa and mix until just incorporated. The batter will be very thick.
  3. Add water to oatmeal and let stand for a few minutes. Once oats are soft, add oats/water mixture to the batter and mix well. Stir in half of the bag of chocolate chips (6 ounces).
  4. Pour into a greased or buttered rectangular 9×13 cake pan. Sprinkle the top of the cake with the rest of the bag of chocolate chips (6 ounces).
  5. Bake at 350 for 30-40 minutes or until the surface springs back lightly when touched and your house smells amazing. Do not overbake. Let cool completely.
  6. For the frosting, melt the butter, sugar, and milk in a large saucepan over medium-low heat. Bring to a boil and boil for 30 seconds.
  7. Reduce heat to low and add chocolate chips and marshmallows. Stir or whisk until frosting is smooth. Pour immediately over the cooled cake. The frosting crystallizes almost immediately as it cools so it’s important to get it on the cake while it’s still piping hot. Allow the frosted cake to cool for 5 minutes before serving. Or… not.


*You can substitute rolled oats for the quick cooking oats, but they should be soaked in the boiling water for at least 10 minutes. Also, if you use rolled oats, the texture of the cake will be different as the oats will be more noticeable.

*Any chocolate chips will work.

*Regular size marshmallows work, too. They just take longer to melt.

  • Prep Time: 15 mins
  • Cook Time: 45 mins
  • Category: Dessert
  • Cuisine: American

Keywords: chocolate cake, chocolate oatmeal cake, oatmeal cake

Guess what else? Mimi is going to need a lot of chocolate cake in the coming months because she’s pregnant with TWIN BABY GIRLS! Chocolate cake and baby girls. That’s the best kind of life.

Thanks Mimi and Mimi’s grandma for letting me share The World’s Best Chocolate Cake with… the world. Yummy.

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  1. Pinch of Yum Logo

    The cake looks and sounds amazing! My mom is a retired MN school teacher and yes, treats in the teacher’s break room went quickly! I can picture the scene with this cake now!

    I want to try it, asap!

    p.s. tried your photo tricks with google, and adding in the world manually, no dice. Darn!

    1. Pinch of Yum Logo

      Thanks Averie! How are you testing the photo thing – just googling the recipe? I have found that it can change over time, so I’ll set the photo tag for a particular photo and it won’t be picked up by Google at first, but then as the post gets more views and comments and moves up in the Google search ranking (which takes a little while for me), Google will grab the photo with the “photo” tag and show it in the search results. Maybe the ones you tried haven’t been picked up by Google yet? Or maybe Google is just a mystery?! We’ll keep working on it and let you if we find anything different. 🙂 Thanks for all your feedback and sharing your experience!

      1. Pinch of Yum Logo


        Thanks for the recipe. I added a little vanilla and a pinch of nescafe on the batter. for my frosting I Had to sub milk for water and did not haveo enough chocolate so it did not crack but tastes delicious! I put the pic on Pinterest!

      2. Pinch of Yum Logo

        Couldn’t find where to comment. I’m techie impaired. I’ve made this cake many times and yes, I bring it to the college I teach at in Oman. It’s gone by 10. I did find halal marshmallows don’t melt properly (and suspect kosher is thesame). I use a recipe for Texas sheet cake glaze instead and it works wonderfully. Thank you for this recipe. I bake a lot of cakes, but this is the staff favorite.

  2. Pinch of Yum Logo

    I’m pretty much known as the cake maker on both sides of my families and at work. If I try to bring something else to potlucks I get a dirty look! This one is going on the list – I love love love icing that hardens up a little bit like this one. Looks delicious!

    1. Pinch of Yum Logo

      I made this cake a week ago for my daughter’s birthday, and everyone loved it. It was delicious. Loved the icing and how moist the cake was. My daughter told me to save the recipe so that we can make it again. Definitely a big hit!

  3. Pinch of Yum Logo

    Free food is the best tasting food, obviously. I’ve been known to grab a stray free sandwich in the kitchen at the office even after eating eating my own lunch. And, this cake looks awesome! Been looking for something different but yet still traditional to make for holiday dessert, and this might be it!

  4. Pinch of Yum Logo

    This cake looks amazing! I have a couple questions though: what size pan did you use, and when you say to sprinkle the chocolate chips is that when you use the whole bag? Maybe I just need to read the recipe again but would love some clarification!

    1. Pinch of Yum Logo

      Half of the bag of chocolate chips get stirred into the batter, and half get sprinkled on top before baking. And then I used a 9×13 pan. 🙂

    2. Pinch of Yum Logo

      I’ve made this cake a few times and I absolutely love it. I was wondering if anyone has tried making it as a layer cake to dress it up? Obviously the frosting would have to be something else too. Sorry I can’t seem to leave well enough alone…

  5. Pinch of Yum Logo

    AH, that is seriously the best kind of icing icing!!!
    And people DO love all free food. I’m 100% guilty right here–I stalk open tables at work, just hoping for a half-empty box of doughnuts to appear. I think it’s the inner college student in all of us.
    Thank you for sharing this delicious recipe. I could so go for double slice right this very instant!

  6. Pinch of Yum Logo

    Sorry for the double comment, but just thought of a quick Q–what size cake pan did you use? Standard 9×13?

    Also, I heart MN. Lived in the Twin Cities for almost 4 years! Did you teach near by at all?

    1. Pinch of Yum Logo

      Double comments welcome! I used a 9×13 aluminum pan. So classy. I don’t have a real cake pan here… so… I guess it’s a testament that just about anything will work. 🙂

  7. Pinch of Yum Logo

    I’m salivating. Seriously.

    There are a ton of teachers in my family and immediate friends (mom, sister, brother-in-law, cousins, etc) and I believe they would agree that this is true 🙂

    It’s also true in many office settings. Bring in a treat, and it’s gone in 60 seconds or less!

  8. Pinch of Yum Logo

    Free food – you’re right, there is a science to it!

    This looks wonderful. But really, it’s chocolate cake – so I suppose that’s quite obvious.

    By the way, I am SO excited for Food Blogger Pro to start in a few months. 🙂

  9. Pinch of Yum Logo

    Oooooh all the chocolate and the oaty texture and flavor! Of course this would be gone in seconds, but not just because it was free to your students…because it’s made out of the best things on the planet and looks absolutely delicious!

  10. Pinch of Yum Logo

    These really does look like the world’s best chocolate cake. I like the fact that the oatmeal makes it seem healthy enough for me to justify having two slices 😉

  11. Pinch of Yum Logo

    Bj, Now it makes sense why the size 33 shorts I sent with Mary to the Philippines were too small for you. Mom

  12. Pinch of Yum Logo

    Oh, no. Now I have to make this. Dang you Lindsay and your “best ever” claims. ‘Cause you’re mostly always right.

    I’m going to make it tonight. And here’s why that’s a problem – ’cause I have half of one of THESE left on my countertop.