Mint Oreo Cake (A Scratch Recipe)

This delicious Mint Oreo Cake is SO good, with mint Oreo cake layers, rich ganache, and mint buttercream frosting.

The result is a super moist, flavorful cake which is sure to please, whether you need a great birthday cake, or just craving something delicious to share with family and friends. 

Why We Love It

There are so many reasons to love this Mint Oreo Cake! Here are just a few:

• Chocolate and Mint are the perfect combination! Check out our Mint Chocolate Chip Cake, Peppermint Patty Cake , Peppermint Bundt Cake, and Peppermint Mocha Cake as well. We also have a great recipe for homemade mint chocolate cupcakes!
• Moist, tender cake thanks to the buttermilk in the recipe.
• Easy ganache glaze adds a bit of drama and makes it feel even more special!
• Makes a great birthday cake recipe, holiday cake, potluck dessert, and more!

How to Make a Mint Oreo Cake

*You can find the full, printable cake recipe further down in this post. Here is a quick rundown of our steps!

Preheat the oven 350 degrees F, grease and flour three 8×2 inch round pans. We like to also add a circle of parchment paper to the bottom of each pan.

Crush the Mint Oreos- I placed them in a ziplock bag and crushed with a rolling pin but you can use a food processor if you'd rather, for finer crumbs.

Next, in a medium bowl, whisk the dry ingredients (cake flour, baking powder, baking soda and salt) for 30 seconds. Set aside

In another bowl, combine the wet ingredients: buttermilk, vegetable oil, vanilla extract, and peppermint extract.  Set aside.

In the bowl of your mixer, add the butter and mix at medium speed until smooth. Slowly add the sugar and continue to mix on medium speed for three to five minutes until lightened and fluffy. (If using a stand mixer, use the paddle attachment).

Add the eggs one at a time mixing until the yellow of the yolk disappears. Add a bit of green coloring gel if you'd like!

Next, with the mixer on low speed, alternately add the flour mixture and buttermilk mixture, beginning and ending with the flour mixture (3 additions of dry ingredients and 2 of liquid). Mix after the last addition, just until combined.

Next, fold in the crushed Mint Oreos.

Scrape down the sides of the bowl with a rubber spatula, and divide the cake batter between the three prepared cake pans.

Bake at 350 degrees for 25-30 minutes or until a toothpick inserted in the center comes out clean or with just few crumbs attached. *If baking in 9 inch pans, bake 25-30 minutes. Let cool in the pans on a wire rack for 10 minutes and turn out.

Filling and Frosting for Mint Oreo Cake

The filling and frosting for our Mint Oreo Cake layers is a mint buttercream frosting and decadent ganache.

For the Ganache

I love to use ganache for adding dramatic drips to cakes, but especially for a boost of decadent chocolate flavor. 

To make this easy ganache, simply combine the chocolate chips and heavy cream in a microwave safe bowl, heat until chips are almost completely melted, and then allow to sit and give it a stir. The mixture will combine to be silky smooth, and will thicken a bit as it cools. 

**We used equal parts of chocolate and cream by weight for our dark chocolate drizzle- If using semi-sweet chocolate, you may want to add slightly more chocolate than cream.

For the Mint Buttercream

This buttercream is so delicious- it works great as a filling or frosting, and can be whipped up in no time. It is based on our Classic Vanilla Buttercream, plus a little peppermint extract.

This is an American buttercream recipe, which means it's just a matter of combining softened butter, sifted confectioners sugar, milk, and extract(s).

Mix for 3-4 minutes on medium speed until fluffy and smooth, and then a minute or two more on low speed to reduce air bubbles.  

**If you'd like to incorporate even more chocolate flavor into the cake, you could also frost it with our Chocolate Buttercream Frosting! 

Assembling the Mint Oreo Cake

Place the first cake layer on the pedestal or cake plate. Spread with a layer of mint buttercream frosting, and then drizzle ganache on top of that, along with additional crushed mint Oreos. 

Top with the second layer of Mint Oreo Cake and repeat the above steps. Top with the third cake layer and frost with a thin coat of mint buttercream. This is often referred to as the crumb coat.

I always chill my cakes in the freezer for 10-15 minutes, or longer in the refrigerator, after applying the first coat of frosting (the thinly applied  crumb coat).

Frosting the Cake

Apply the second coat of frosting, smooth with metal bench scraper and chill for 5-10 minutes more. 

Then, glide back over it with a spatula or bench scraper that has been heated under hot water. This technique is known as the Hot Knife Method of Smoothing.

The finish of your frosting doesn't have to be flawless, just smooth enough that the ganache drip will be able to easily flow down from the top edge of the cake.

Applying the Ganache Drip

Apply the ganache drip around the top edge of the cake, using a piping bag with the very tip snipped away.

You can do a trial run on the inside of a bowl to see if the ganache needs to be warmed or cooled to reach the desired consistency for dripping. (It should not be hot when applied to cake). See our Ganache Drip Tutorial for more details!

After applying the drip all the way around, spread additional ganache on top of the cake.

I added a little spiral pattern on top using a spoon as I rotated the cake on a turntable. (We demonstrate ta version of this spiral look in our Ridged Buttercream Cake tutorial.)

I added half of a mint Oreo cookie to the center of the cake, and added a small bead border piped with a small round tip 3 around the bottom of the cake.

(You can learn about bead borders in our Basics of Piping with Round Tips tutorial!)

You can find the full roundup of our FAVORITE chocolate cakes here: Best Chocolate Cake Recipes

Enjoy the Recipe

Thanks so much for stopping by! Don't miss our full collection of Cake Recipes, including delicious cake recipes from scratch as well as cake mix recipes!

Mint Oreo Cake {A Scratch Recipe}

BY Melissa and Bebe

This moist Mint Oreo Cake with ganache and mint buttercream is the best! If you love the delicious combination of mint and chocolate, you will love this recipe!

Prep Time: 15 minutes mins

Cook Time: 30 minutes mins

Course: Dessert

Servings: 15 servings

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Equipment

• ▢
  Wilton Piping Tips Set (These can be purchased individually as well) 
• ▢
  Wilton Disposable Piping Bags- 12 inch
• ▢
  Magic Line Pans- 8 inch

Ingredients

For the Cake Layers

• ▢ 1 ½ sticks unsalted butter, softened (170g) (holds it shape but dents when pressed)
• ▢ 2 cups sugar (400g)
• ▢ 4 eggs, room temperature (place in a bowl of warm water if in a hurry)
• ▢ 3 cups cake flour (342g)(If not using a digital scale, lightly spoon into measuring cup and level off ). See substitution in notes if needed.
• ▢ 2 teaspoons baking powder (8g)
• ▢ ½ teaspoon baking soda (3g)
• ▢ ½ teaspoon salt (3g)
• ▢ 1 ¼ cups buttermilk (296g) See substitution in notes if needed.
• ▢ ¼ cup vegetable oil (54g)
• ▢ 1 Tablespoon vanilla extract (12g)
• ▢ 2 ½ teaspoons Peppermint Extract (10g)
• ▢ 10 Mint Oreos, crushed (109g) (If you cannot find mint Oreos, use regular) Place in ziplock bag and crush with rolling pin, or use a food processor for finer crumbs.
• ▢ Green Coloring Gel I used Wilton Leaf Green

For the Ganache Drip

• ▢ 6 oz Chocolate (Semi-sweet or Dark) We used Ghirardelli Dark Chocolate Chips (171g)
• ▢ 6 oz Heavy Cream (171g)

For the Mint Buttercream Frosting

• ▢ 3 sticks unsalted butter (354g)
• ▢ 8 cups powdered sugar (920g)
• ▢ 1 teaspoon Peppermint Extract (Adjust amount to your liking. (flavor will intensify slightly over time.) (8g)
• ▢ ½ to 1 teaspoon salt optional to cut sweetness
• ▢ ¼ cup milk (adjust based on desired consistency) (60g)

Assembly/Decoration

• ▢ Additional Crushed Mint Oreos sprinkled between the cake layers
• ▢ Disposable piping bag for ganache drip
• ▢ We used a small round piping tip 3 for the bead border at the base of the cake
• ▢ Offset spatula or bench scraper for smoothing the frosting and spreading ganache.

Instructions

For the Mint Oreo Cake Layers

• Preheat the oven 15-20 minutes to 350 degrees, grease and flour three 8×2 inch round pans, adding a circle of parchment paper in the bottom of each pan.
• Place Oreos in a ziploc bag or between two sheets of waxed paper and crush with a rolling pin.
• In a medium bowl, whisk the flour, baking powder, baking soda and salt for 30 seconds. Set aside
• In another bowl, add the buttermilk, oil, vanilla and peppermint extract.  Set aside..
• In the bowl of your mixer, add the butter and mix at medium speed until smooth. Gradually add the sugar and continue to mix on medium speed for 3 to 5 minutes until lightened in color and fluffy. Add the eggs one at a time mixing until the yellow of the yolk disappears.
• Alternately add the flour mixture and buttermilk mixture, beginning and ending with the dry ingredients (3 additions of dry ingredients and 2 of liquid).
• Add green coloring gel if you'd like.
• Do not mix above medium speed or over mix the cake batter.
• Fold in the crushed Mint Oreos. Divide batter between your pans.
• Bake at 350 degrees for 25-30 minutes or until a toothpick inserted in the center comes out clean or with just few crumbs attached. *If baking in 9 inch pans, bake 25-30 minutes. Let cool 10 minutes and turn out.
• This recipe makes 8 cups of batter

For the Ganache

• Place your chocolate into a microwave safe bowl.
• Pour heavy cream over the chocolate and place in the microwave for 1 minute. (Times may vary, see our note below).
• Remove and stir. Microwave for 30 seconds more if needed and when the chocolate has melted almost completely, allow it to sit for 1 minute more before stirring. Stir until you've reached a silky smooth consistency.
• *Microwave times may vary. If you are making a smaller amount of ganache, you will reduce the microwave time. If your chocolate hasn't melted after the 1 ½ minutes recommended in the instructions, simply microwave in small 10-15 second increments until it has nearly completely melted. Let sit one minute, then stir until smooth.

For the Mint Buttercream

• Cream the (slightly softened) unsweetened butter until smooth.
• Blend in the peppermint extract.
• Add half of the powdered sugar and most of the milk. Beat at medium speed until the powdered sugar is incorporated.
• Add remaining powdered sugar and milk and mix at medium speed another 3 to 4 minutes scraping the sides of the bowl occasionally. I slow down the mixer to very slow. (#2 on the Kitchenaid) for 1 to 2 minutes. This will help eliminate air pockets in the buttercream. The texture will become very smooth.
• If your buttercream is too thin, add more powdered sugar. If the consistency is too thick, add a bit more milk.

Assembling the Cake

• Place the first cake layer on the pedestal or cake plate.
  Spread with a layer of mint buttercream frosting, and then drizzle ganache on
  top of that, along with additional crushed Mint Oreos. 
• Repeat for the next cake layer, and top with the third cake layer. Crumb coat the cake with Mint Buttercream. (At this point I like to chill the cake in the freezer for 10-15 minutes).
• Apply the second coat of frosting, smooth with bench warm metal scraper (or
  your preferred method), and chill for 5-10 minutes more. 
• Apply the ganache drip around the top edge of the cake, using a piping bag
  with the very tip snipped away. (Ganache should not be hot).
• After applying the drip all the way around, spread additional ganache on top
  of the cake.
• I added half of a mint Oreo to the center of the cake for decoration, and added a small
  bead border piped with a small round tip 3 around the bottom of the cake.

Notes

Substitute for Buttermilk: No Buttermilk? Here is a substitution: To a measuring cup, add 1 Tablespoons vinegar or lemon juice. Add milk to the 1 ¼ mark, stir. Wait 5 minutes and it is ready to use.

Substitution for Cake Flour: Using all purpose flour (plain in UK) to make Cake Flour: For each cup of flour in a recipe, remove 2 Tablespoons of flour and replace with 2 Tablespoons cornstarch (cornflour in the UK). This recipe has 3 cups of flour so you will measure out 3 cups of all purpose flour, remove 6 Tablespoons and replace with 6 Tablespoons cornstarch, whisk to blend

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