This incredibly easy Oreo sheet cake is a crowd-pleaser for birthdays, barbecues, and gatherings of all kinds. It’s one I come back to again and again, and I always get at least one request for the recipe.
I’ve been making this oreo sheet cake for years and it’s the best cake for large groups, but I’ve always hesitated to share the “recipe”, because it’s just barely a recipe. It’s more like a cheat code for making a quick and easy dessert for a big group by assembling a few different store-bought items. Everyone just loves it, though, and I do get a lot of requests for the recipe, so I thought it was time to put it down in writing. This Oreo cake started as a favorite for barbecues or festive family house parties and ended up being requested as a birthday cake by a few different kids in our neighborhood, so I’ve reluctantly had to share how I made it and how ridiculously easy it is.
I probably would have prefered to keep the secret a little longer, because the end result tastes like something really special. The truth is though, that it’s nothing fancy!
More essential recipes for chocolate lovers: Double Chocolate Chip Cookies With Roasted Almonds
Ingredients You’ll Need for the Oreo Sheet Cake
- Boxed chocolate cake mix prepared according to package instructions
- Store-bought vanilla icing in a can
- Oreo cookies (regular size and mini)
It really is almost silly to call this a recipe, but it really is worth sharing because everyone just seems to gather around when you bring this decadent, almost homemade chocolate dessert out at the end of a meal.
The only thing I’ll note about the ingredients is that when I prepare the boxed cake mix, if it calls for regular vegetable oil, I substitute melted unsalted butter or a plant-based substitute. I also always use a plant-based substitute for the eggs (either store-bought or I just use chia seeds).
If you’re looking for a dessert that’s technically plant-based this one will fit the bill when the cake is baked with plant-based substitutes for any dairy or egg products. Most cakes or cupcakes that come as boxed mixes and pre-made frostings are plant-based, and Oreos are accidentally vegan as well. While it’s definitely indulgent and not the healthiest option, this is the best chocolate cake for when you want to bring something out that everyone will get excited about.
Try this recipe next: Easy 3 Ingredient Banana Bread Recipe
Assembling the Easy Sheet Cake Recipe
First you’ll need to prepare the chocolate cake mix in a 9×13 baking dish. This is a great time to use your best cake pans because you’ll serve the cake right in the dish you bake it in. Whisk together the mix, melted butter, eggs, and water according to the package instructions. Continue stirring until most of the lumps are broken up, then pour the batter into your baking dish, using a rubber spatula to get every last bit of batter out of your mixing bowl. I don’t usually even bother getting out my stand-mixer for this step because it’s so easy to do by hand.
Bake the cake until a toothpick inserted into the middle comes out clean and allow it to cool completely on a wire rack or overnight in the refrigerator.
When you’re ready to finish the cake, empty out the room temp canned vanilla icing into a big mixing bowl. Transfer the contents of your package of regular-size Oreos into a sturdy zipper freezer bag and crush them with a rolling pin. Leave some big chunks of cookie uncrushed for added deliciousness and visual appeal.
Whip the crushed cookie crumble into the icing until everything is consistently well-distributed and the frosting is whipped up and fluffy. Using a large spoon, add dollops of the Oreo frosting evenly across the top of the cooled cake and use a knife or a spatula to spread it out in a thick, dense layer across the entire cake.
See also: Cake Mix Pudding Cookies
Use the mini Oreos to decorate the top of the cake, ideally placing them where each slice will get one little cookie. Sprinkle with a dusting of cocoa powder for an extra chocolatey presentation if you like.
More clever cooking shortcuts: Favourite Kitchen Tricks That Save Time and Money
Variations on This Easy Dessert Recipe
Once you’ve tried the basic version of this easy cake recipe, you can get creative and try different variations for different occasions using the same method.
Use a white cake mix and mix in crumbled store-bought chocolate chip cookies to the icing for a cookie dough vanilla cake. Use mint oreos and mix in a bit of peppermint flavoring to the icing for a festive Christmas peppermint oreo cake. Use a strawberry icing and top the cake with whole strawberries for a chocolate-covered strawberry cake that will look perfect for Valentine’s Day.
Other options to consider would be to try buttercream, chocolate frosting, marshmallow, or cream cheese frosting with a red velvet cake mix. You could create an Oreo mocha fudge cake by adding instant espresso to the frosting along with an easy icing sugar chocolate drizzle on top, or a chocolate nut cake by mixing in walnuts or chocolate peanut butter candy pieces.
The options for switching this cake up to make something entirely new are limited only to your imagination and what easy pre-made finds you can come across in your local grocery store when you need a quick and fun dessert. Turn your kitchen into the test kitchen for these easy sheet cake ideas and your friends and neighbours will definitely be excited to help you sample them all.
Here’s the full printable recipe.
This incredibly easy Oreo sheet cake is a crowd-pleaser for birthdays, barbecues, and gatherings of all kinds. It's one I come back to again and again, and I always get at least one request for the recipe.
- 1 Boxed chocolate cake mix (prepared according to package)
- 2 cans Store-bought vanilla icing
- 1 package Oreo cookies
- 1/2 package Mini Oreo cookies (optional, to decorate)
Prepare the boxed cake mix in a 9"x13" baking dish and bake at 350° until a toothpick inserted in the middle comes out clean. Allow to cool completely.
Empty both cans of vanilla frosting into a large mixing bowl. Transfer the package of regular Oreo cookies into a sturdy freezer bag and use a rolling pin to crush them, leaving a few big chunks here and there. Mix the crushed Oreos into the frosting until everything is well combined.
Use a spoon to place large dollops of the icing/Oreo mixture all across the top of the cake, then spread it out evenly in a thick layer across the entire cake.
Decorate the cake with the mini Oreos and chill in the refrigerator until you're ready to serve.
Courtenay Hartford is the author of creeklinehouse.com, a blog based on her adventures renovating a 120-year-old farmhouse in rural Ontario, Canada. On her blog, Courtenay shares interior design tips based on her own farmhouse and her work as founder and stylist of the interior photography firm Art & Spaces. She also writes about her farmhouse garden, plant-based recipes, family travel, and homekeeping best practices. Courtenay is the author of the book The Cleaning Ninja and has been featured in numerous magazines including Country Sampler Farmhouse Style, Better Homes and Gardens, Parents Magazine, Real Simple, and Our Homes.