Chocolate and mint are a classic pair, and this Dreamy Mint Chocolate Sheet Cake makes that combination even better! It starts with my Perfect Chocolate Sheet Cake, a rich and moist chocolate cake that is easy to make and always a favorite. This version is topped with a creamy mint buttercream frosting and plenty of chocolate chips for a fun, bakery-style dessert you can make at home.
The soft chocolate cake, cool mint flavor, and little bites of chocolate make every slice feel special. If you enjoy the combination of chocolate and mint, my layered Mint Chocolate Cake is another delicious dessert to try!
Ingredients & Substitutions
- All-Purpose Flour: Flour gives the cake structure while keeping it soft and tender. For the best results, measure it carefully by spooning it into a measuring cup and leveling it off.
- Granulated Sugar: Sugar sweetens the cake and helps keep it moist.
- Unsweetened Cocoa Powder: Cocoa powder gives the cake its rich chocolate flavor. Use a good-quality cocoa powder for the best chocolate taste. This is where most of the chocolate taste comes from, so it’s worth using one you like.
- Baking Soda and Baking Powder: These help the cake rise and give it a light, soft texture.
- Kosher Salt: Salt balances the sweetness and helps bring out the chocolate flavor.
- Buttermilk: Buttermilk adds moisture and helps create a soft, tender cake. If needed, you can use a homemade buttermilk substitute by adding a little lemon juice or vinegar to milk.
- Vegetable Oil: Oil keeps the cake moist and gives it a soft texture. You can substitute another neutral-flavored oil, such as canola oil.
- Eggs: Eggs help hold the cake together and add richness. Room-temperature eggs mix more evenly into the batter.
- Vanilla Extract: Vanilla enhances the chocolate flavor and adds a warm sweetness.
- Hot Coffee or Hot Water: Hot coffee helps bring out the rich chocolate flavor in the cake. Don’t worry, the cake will not taste like coffee! The coffee simply makes the chocolate taste deeper and more intense. You can use hot water instead if you prefer.
- Mint Buttercream Frosting: This creamy frosting adds the sweet peppermint flavor that makes this cake extra special. Start with a small amount of peppermint extract and add more if desired, because a little mint flavor goes a long way.
- Chocolate Curls: Chocolate curls add a lovely chocolate finish on top of the frosting. You can also use finely chopped dark chocolate or mini chocolate chips if you prefer.
Tips for the Best Mint Chocolate Sheet Cake
- Use room-temperature ingredients: Room-temperature buttermilk and eggs mix more evenly into the batter, helping create a smooth, tender cake.
- Do not overmix the batter: Once the ingredients are combined, mix just until the batter is smooth. Overmixing can make the cake less tender.
- Do not worry about the thin batter: This chocolate cake batter is thinner than many cake batters. That is normal and helps create a soft, moist cake.
- Use hot coffee for the best chocolate flavor: The coffee will not make the cake taste like coffee. It simply helps bring out a deeper, richer chocolate flavor. Hot water can also be used.
- Do not overbake the cake: Start checking the cake around 28 minutes. It is done when a toothpick inserted in the center comes out with a few moist crumbs.
- Let the cake cool completely before frosting: If the cake is still warm, the mint buttercream can melt and become difficult to spread.
- Start with less peppermint extract: Mint flavor can become strong quickly. Add a little at a time until it reaches the flavor you like.
FAQs
Does this cake taste like coffee?
No! The coffee does not make the cake taste like coffee. It simply enhances the chocolate flavor and makes the cake taste richer and more chocolatey. You can use hot water instead if you prefer.
Can I make this cake in a different-sized pan?
Yes, this cake can be baked in a different-sized pan, but the baking time will need to be adjusted. A smaller pan will make a thicker cake and may need more time to bake, while a larger pan will make a thinner cake and may bake faster. Keep an eye on the cake and test it with a toothpick when you think it is close to done.
Can I make the mint flavor stronger?
Yes! If you love a stronger mint flavor, you can add a little more peppermint extract to the frosting. Add it slowly and taste as you go because peppermint extract is very strong and a little goes a long way.
Can I make this cake without mint?
Absolutely. You can leave out the peppermint extract and make a delicious chocolate sheet cake with chocolate frosting or another favorite frosting instead.
Can I make the frosting without food coloring?
Yes! The green food coloring is only used to give the frosting a classic mint chocolate chip look. It does not add flavor, so you can leave it out if you prefer. The frosting will still be creamy, delicious, and full of mint flavor.
Can I freeze Mint Chocolate Sheet Cake?
Yes! Freeze the cake with the mint buttercream frosting, but wait to add the chopped chocolate topping until after thawing for the best texture and appearance. Cover the cake tightly and freeze for up to 3 months. Thaw in the refrigerator or at room temperature before serving.
How to Store Mint Chocolate Sheet Cake
Room Temperature: Store the covered cake at room temperature for up to 2 days. Keep it in an airtight container or cover it tightly with plastic wrap to help keep the cake soft and moist.
Refrigerator: For longer storage, cover and refrigerate the cake for up to 5 days. Let the cake sit at room temperature for a little before serving for the best texture and flavor.
Freezer: Freeze the cake for up to 3 months. For the best results, freeze the cake with the mint buttercream frosting, but wait to add the chopped chocolate topping until after thawing. Cover the cake tightly with plastic wrap and place it in a freezer-safe container. Thaw before serving and add the chocolate topping just before enjoying.
Dreamy Mint Chocolate Sheet Cake
Ingredients
Chocolate Cake
- 1 ¾ cups (219 g) all-purpose flour
- 2 cups (400 g) granulated sugar
- ¾ cup (90 g) unsweetened cocoa powder
- 2 teaspoons baking soda
- 1 teaspoon baking powder
- 1 teaspoon kosher salt
- 1 cup (240 g) buttermilk, room temperature
- ½ cup (112 g) vegetable oil
- 2 large eggs, room temperature
- 2 teaspoons vanilla extract
- 1 cup (237 g) hot coffee or hot water
Mint Buttercream Frosting
- ½ cup (1 stick / 113 g) unsalted butter, softened
- 4 cups (500 g) confectioners' sugar
- ¼ teaspoon kosher salt
- ½ teaspoon peppermint extract, adjust to taste
- 6 to 8 tablespoons whole milk, as needed for a creamy, spreadable consistency
- 2 to 4 drops green gel food coloring
Topping
Instructions
Chocolate Cake
- Preheat oven to 350°F (175°C). Spray a 9×13-inch baking pan with nonstick cooking spray.
- In the bowl of a stand mixer, whisk together the flour, sugar, cocoa powder, baking soda, baking powder, and salt.
- In a separate bowl, whisk together the buttermilk, oil, eggs, and vanilla extract.
- With the mixer on low speed, slowly add the wet ingredients to the dry ingredients. Mix until just combined.
- Carefully add the hot coffee (or hot water) and mix on low until smooth. The batter will be thin; this is normal.
- Pour the batter into the prepared pan. Bake for 28 to 32 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs.
- Let the cake cool completely in the pan on a wire rack.
Mint Buttercream Frosting
- In a medium bowl, beat the butter until creamy.
- Gradually add the confectioners’ sugar and salt, mixing on low until combined.
- Add the peppermint extract and 6 tablespoons of milk. Beat until smooth and creamy. Add additional milk, one tablespoon at a time, until the frosting reaches a spreadable consistency.
- Add the green food coloring and beat until the color is evenly mixed. Add more food coloring, a little at a time, until you reach your desired shade.
- Taste and add more peppermint extract if desired. Start with a small amount because peppermint flavor becomes stronger quickly.
- Spread the frosting evenly over the cooled cake.
- Sprinkle the chocolate curls over the frosting.
- Let the cake rest for 15 to 30 minutes before serving to allow the chocolate to settle slightly into the frosting.
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