Thin Mint Sheet Cake

Thin Mint Sheet Cake

I am so in love with sheet cake.

The problem with layer cakes is that beauty often takes the place of function. They have to be gorgeous, so we pile on way too much frosting or fondant and then decorate the whole shebang. A sheet cake, however, is the perfect ratio of cake to frosting (or in this case, icing). The cake is the star, not its good looks.

And it definitely doesn’t hurt that  this one is topped with chopped Thin Mints. America’s favorite Girl Scout cookie is ready for her moment in the sun!

Thin Mint Sheet Cake

When I was a kid, sheet cakes meant birthdays. My mom is not the most enthusiastic baker, so she would take a Duncan Hines cake mix (the brand is known as “Uncle Duncan” in my family), put it into a sheet cake pan, and cover it with ready-made frosting. She also bought those sugar letters you get in the cake aisle and put them on our cakes.

I loved it. While the grown-up me tends to make fancy layer cakes for birthdays, I’ve never lost that soft spot for a sheet cake in a pan. They’re simplicity itself.

Thin Mint Sheet Cake

The problem with a chocolate cake is that it’s simply too addictive. I like to put the cake in the fridge once it cools and then once it’s chilled, everyone attacks it. Open season on cake! Did you ever see that Sex and the City episode where Miranda bakes a chocolate cake? She spends the entire episode eating way more of it than she wants to, and the whole thing ends with her dumping the cake in the trash and covering it with dish soap.

I always feel sad when Miranda destroys the cake, but I understand it. A layer cake is too decadent to munch on for any length of time. But you can cut sliver after sliver off a sheet cake and never get tired of it.

Thin Mint Sheet Cake

If you’re a regular reader here on JAB, you know that mint is not my favorite. But I can’t resist baking with Thin Mints for everyone else. They get so excited when they realize that not only is there a baked good in sight, but that it also contains one of their favorite limited-edition GS cookies.

Thin Mint Sheet Cake

This cake is very simple. It’s my favorite chocolate cake base (thanks, back of the Hershey cocoa container!) covered with an equally easy icing and chopped Thin Mints. I think the most labor-intensive part of this baking experience was chopping the Thin Mints. Be sure you dump even the crumbled insides of the Thin Mints on the cake, by the way. It really adds to you topping.

When all is said and done, we always come back to the desserts we loved as children. I am a sheet cake devotee and don’t plan on changing that love anytime soon. Thanks for the birthday cakes, Mommy!


Thin Mint Sheet Cake


2 cups sugar
1 and 3/4 cups flour
3/4 cup cocoa
1 and 1/2 teaspoons baking soda
1 and 1/2 teaspoons baking powder
1 teaspoon salt
1 cup milk
1/2 cup oil (I used canola)
2 teaspoons vanilla
2 eggs, lightly beaten
1 cup boiling water
1/2 cup chocolate chips
1 tablespoon butter
1 and 1/2 cups powdered sugar
5 tablespoons water, divided
1 sleeve (1/2 package) Thin Mints, chopped


  1. Preheat the oven to 350. Coat a 9 x 13-inch pan with cooking spray. Set aside.
  2. Combine the sugar, flour, cocoa, baking soda, baking powder and salt in a bowl.
  3. Stir in the milk, oil, vanilla and eggs, mixing until smooth.
  4. Fold in the boiling water carefully.
  5. Pour the batter into the prepared pan. Bake until a toothpick inserted comes out clean, about 35-40 minutes.
  6. Allow the cake to cool completely. When the cake is cool, prepare the glaze. Melt the chocolate in a saucepan with the butter and 2 tablespoons of water. When it's melted, take the pot off the heat and stir in the powdered sugar. Add the remaining tablespoons of water and stir until smooth.
  7. Allow the glaze to thicken for about 15 minutes. When it's a little thicker, pour the glaze over the cake. Immediately sprinkle the chopped Thin Mints on top Let the glaze set.
  8. Cut into squares and serve.


I fulfill many roles in life: wife, mother, teacher, everlasting learner. This site is dedicated to one role that expresses my creativity in ways that I find consistently challenging and rewarding: baker. Inventing new ways to enhance food, especially if that food involves chocolate or peanut butter (or both!), is a passion of mine. I look forward to sharing my ideas with you.

This Post Has 34 Comments

  1. Dorothy @ Crazy for Crust

    I can eat an entire chocolate cake in a sitting. Add Thin Mints? I’m DOOMED!
    Dorothy @ Crazy for Crust recently posted…Extreme Oreo Stuffed Peanut Butter CookiesMy Profile

    1. Mir

      Yeah, they go down too easy. Get this cake outta my fridge! 🙂

  2. Gayle @ Pumpkin 'N Spice

    Thin mints are the best! Love this creative cake!
    Gayle @ Pumpkin ‘N Spice recently posted…Corned Beef Hash and EggsMy Profile

    1. Mir

      Thanks, Gayle! I love them on cake!

  3. Kate @ Framed Cooks

    First of all, I MISS SEX AND THE CITY. Second, I volunteer to take any and all mint things off your hands, especially anything and everything involving Thin Mints. Gotta make this one!
    Kate @ Framed Cooks recently posted…Shrimp Barley Risotto with PeasMy Profile

    1. Mir

      It was such a good show, Kate. I watch reruns sometimes but it’s no longer as shocking as it once was!

  4. Dannii @ Hungry Healthy Happy

    I have never had a thin mint before, but I love chocolate and mint together!
    I love cakes like this, as I don’t think even I could mess up the presentation.
    Dannii @ Hungry Healthy Happy recently posted…Comment on Spanish Butterbean and Spinach Stew by IsabellaMy Profile

    1. Mir

      If you like that combo, you’d love this!

  5. Cakespy

    This looks like the best sheet cake idea EVER! Love this creative interpretation of the thin mint flavor.
    Cakespy recently posted…The Unicorn Coloring BookMy Profile

    1. Mir

      Thanks, Jessie! I’m always up for sheet cake. Always.

  6. Cheyanne @ No Spoon Necessary

    Hahaha! I DO remember that episode of Sex and the City! And it’s so true.. a sheet cake is dangerous stuff to have around! Love this sheet cake, Mir! The GS thin mints here are genius! My hubs and mom are huuuuge fans of that cookie, so I’m willing to bet they would polish this sheet cake off in about .5 seconds! Cheers, doll!
    Cheyanne @ No Spoon Necessary recently posted…Cinnamon Maple Chia Seed Pudding with Bananas Foster ToppingMy Profile

    1. Mir

      I have it waiting for me at home and I’m afraid of being alone with it! 🙂

  7. annie@ciaochowbambina

    You are right on…we do come back to the desserts we loved as children. I have such a soft spot for chocolate chocolate cake (Uncle Duncan, of course!), peanut butter cookies and lemon meringue pie. I don’t know the last time I had a GS cookie – but you’ve convinced me to grab a box! This cake is too good!
    annie@ciaochowbambina recently posted…Soul SnacksMy Profile

    1. Mir

      Peanut butter cookies will always have a special place in my heart, too!

  8. Megan - The Emotional Baker

    Can you believe I’ve never made a sheet cake?!? But you are so right. Layer cakes are sometimes just too much trouble! This Thin Mint flavor is amazing!

    1. Mir

      Thanks, Megan. I don’t want to put labor into my cake all the time!

  9. Medha @ Whisk & Shout

    This sheet cake looks amazing and my favorite part is how quickly it comes together! I’ve asked my mom to put a couple boxed of Girl Scout cookies on reserve for when I’m on break 🙂
    Medha @ Whisk & Shout recently posted…Green Tea Sesame Soba Noodles with Stir Fried TofuMy Profile

    1. Mir

      Your mom sounds like a very nice person. I’d eat all the boxes before you got home! 😉

  10. Shashi at RunninSrilankan

    Haha – I so remember that episode where Miranda made that chocolate cake – but, Mir, if I had this in front of me, I don’t think I’d be able to show much -if any- restrain! I adore the combo of mint and chocolate and I am a huge supporter of the fact that “The problem with a chocolate cake is that it’s simply too addictive”! 🙂
    Shashi at RunninSrilankan recently posted…Salted, Chocolate-Drenched, Spicy, Sweet Potato FriesMy Profile

    1. Mir

      Yeah, it’s just sitting in my fridge taunting me. I think it’s gonna be dinner later…healthy!

  11. Rachelle @ Beer Girl Cooks

    Can you believe that I’ve never seen a single episode of Sex in the City? I can certainly relate to the need to trash a chocolate cake with dish soap to stop myself from eating it all! I also love the simplicity of a sheet cake and this chocolate looks dangerous – especially with all those Thin Mints on top!

    1. Mir

      Aaaah, Rachelle, take a break from GH and watch Sex and the City! You need to give it a shot. It’s a little dated at this point, but still lots of fun!

  12. Manali @ CookWithManali

    gosh, I am afraid I would eat the entire pan if this was in front of me!!
    Manali @ CookWithManali recently posted…Homemade Burger BunsMy Profile

    1. Mir

      That is definitely the problem I’m having here! 🙂

  13. Alice @ Hip Foodie Mom

    Mir, “Uncle Duncan” . . haha, I love it! that Sex and the City episode where Miranda bakes a chocolate cake? oh my gawd, loved that one. . and I have been there! having to throw cake away so I will stop eating it! crazy! I love this thin mint sheet cake! can’t go wrong with thin mints on top .. love this!!! this is a cake I would definitely not be able to resist!
    Alice @ Hip Foodie Mom recently posted…Cauliflower Pesto ToastsMy Profile

    1. Mir

      It’s a great episode. I get hungry just watching it! And now I have my own cake in the fridge, just begging to be eaten. I have to try and forget it’s there!

  14. David @ Spiced

    Chocolate cakes are indeed way too addicting, Mir! I can’t speak for the Sex and the City episode (imagine that!), but I can say that chocolate cake is an ultimate weakness around here. And thin mints have been my favorite Girl Scout cookie since the beginning of time…so the combo is deadly! Well done…oh, and pass me a slice, please? 🙂
    David @ Spiced recently posted…Pulled Pork TostadasMy Profile

    1. Mir

      But I ate it all, David. 🙂

  15. Amanda

    I am going to have dreams about this amazing frosting. What a delicious sheet cake. And I think you hit the sweet spot for a flakey moist cake. Pardon my rumbling stomach.
    Amanda recently posted…Chocolate Chip Molasses BlondiesMy Profile

    1. Mir

      Just had some, Amanda. You are pardoned! 🙂

  16. Michele @ Alwayzbakin

    Mir, you’ve definitely outdone yourself with this recipe. I have my husband drooling here next to me. He LOVES thin mints. And chocolate cake! Yum!
    Michele @ Alwayzbakin recently posted…Lemon Blueberry Loaf CakeMy Profile

    1. Mir

      Ha. Tell him he can have mine! It’s not my fave, sadly.

  17. Sneha

    Is it a need of more no of eggs while we double the weight of flour? Our joint family requires more no.thats why. I think egg for softness right? Or got any extra advantage of using in this recipe??
    Sneha recently posted…GATE 2016 Result.Check HereMy Profile

    1. Mir

      If you need more cake, double the entire recipe. I wouldn’t advise doubling certain ingredients and not others, or you’ll throw off the whole cake. Eggs add moisture to the cake as well as texture. I wouldn’t leave them out or it’s just not the same recipe any more. Hope that helps!

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