Mint Chocolate Cake
Irresistibly moist layers of chocolate cake filled with fluffy mint Oreo mousse, frosted in mint buttercream, and enrobed in dark chocolate ganache!
Ingredients
Chocolate Cake:
- 1 cup boiling water
- 1 ½ teaspoon instant espresso powder
- 3 ounces semi-sweet chocolate, chopped or chips
- 1 ⅔ cup all-purpose flour
- 1 ¾ cup granulated sugar
- ¾ cup unsweetened cocoa powder
- 1 teaspoon baking soda
- 1 teaspoon baking powder
- 1 teaspoon salt
- 2 large eggs
- 1 cup buttermilk*
- ½ cup vegetable oil
- 1 ½ teaspoon vanilla
Mint Buttercream/Filling:
- 1 ¾ cup unsalted butter
- ¼ teaspoon salt
- 5 ½ cup powdered sugar
- 1 teaspoon vanilla
- ¼ teaspoon mint extract
- ½ cup heavy cream
- Green and blue food coloring**
- 4 ounces cream cheese
- ¾ cup heavy cream, whipped
- 8 Mint Oreos, coarsely chopped
Ganache:
- 3 ounces semi-sweet chocolate, chopped or chips
- ⅓ cup heavy cream
For Assembly:
- Mint Oreos
- Andes Mints
Instructions
Make the Cake:
- Preheat the oven to 350ºF. Line four 6-inch round cake pans with parchment paper and grease with butter or nonstick cooking spray; set aside.
- In a medium bowl, stir the boiling water, espresso powder, and semi-sweet chocolate together until chocolate has dissolved and mixture is smooth. Set aside to cool.
- In a large mixing bowl, whisk the flour, sugar, cocoa powder, baking soda, baking powder, and salt together until combined.
- In another bowl, whisk the eggs, buttermilk, vegetable oil, and vanilla together. Pour wet ingredients into the dry ingredients and stir until smooth. Add the cooled espresso-chocolate mixture, stirring until just combined.
- Divide batter evenly among the four pans and bake in the oven for 30-35 minutes, or until a toothpick inserted in the center of the cake comes out clean. Remove from the oven and allow to cool completely before flipping out of pans and onto a wire rack.
Make the Buttercream/Filling:
- In the bowl of a stand mixer fitted with the paddle attachment, beat the butter and salt on high until fluffy, about 4 minutes. Add the powdered sugar, a cup at a time, until fully incorporated. Mix on high for 3 minutes. Add the vanilla, mint extract, and heavy cream and continue beating until fluffy, about 2 minutes.
- Remove 1 cup of the frosting and set aside for the filling. Add food coloring to the bowl of buttercream and beat until combined. Transfer buttercream to a separate bowl, then return bowl to mixer.
- In the mixer, beat the cream cheese and reserved 1 cup of buttercream on high until creamy. Add half of the whipped cream, and continue beating until combined. Remove bowl from mixer, and fold in the rest of the whipped cream along with the chopped Oreos.
To Assemble:
- Place one cake layer on cake pedestal or plate. Top with 1/3 of the filling. Repeat with the remaining cake layers and filling. Place filled cake into the freezer for at least an hour to firm up the filling as well as to ensure easier frosting.
- Remove cake from freezer, frost top and sides with a thin layer of buttercream--this will be the crumb coat. Return to freezer for 30 minutes or until buttercream is solid. Remove cake from freezer and frost with another layer of buttercream.
- Make the ganache by placing the chocolate in a medium bowl. Pour the heavy cream into a glass measuring cup, and heat in the microwave until it just starts to boil. Pour hot cream over the chocolate, cover with plastic wrap, and allow it to sit for a few minutes. Remove the plastic wrap and stir until smooth.
- Using a small spoon, carefully pour the ganache along the edges of the cake, allowing the ganache to drip down the sides.**** Once the sides are done, pour a few tablespoons of the ganache into the center of the cake, and use an offset spatula to fill in the top of the cake.
- Decorate the cake with remaining frosting and Andes mints. Slice, serve, and enjoy!
- If not serving right away, cake can be wrapped loosely with plastic wrap and stored in the refrigerator for up to a week.
Notes
*Buttermilk can be substituted by adding 1 Tablespoon of vinegar or lemon juice to a glass measuring cup, and then pouring in enough milk to the 1 cup measuring line.
**I used a mix of green and blue food coloring to achieve a "minty" pastel color.
***If your cake feels unstable/wobbly after it's fully-frosted, stick 3 long skewers into the cake--it should form a triangle. This will ensure that your cake doesn't lean or shift.
****If the ganache runs down the sides of the cake too quickly, return the cake to the freezer for about 15 minutes. Chilling the cake will slow down the drip.