Chocolate Sheet Cake With Cocoa

Name: Chocolate Sheet Cake With Cocoa
Prep time: 20 min
Cook time: 30 min
Total time: 50 min
Yield: 12 servings
Ingredients: 1 ¾ cups all-purpose flour; 2 cups granulated sugar; ¾ cup unsweetened cocoa powder; 1 ½ teaspoons baking soda; 1 teaspoon baking powder; 1 teaspoon salt; 2 large eggs; 1 cup buttermilk; ½ cup vegetable oil; 2 teaspoons vanilla extract; 1 cup boiling water; ½ cup unsalted butter, softened; ⅔ cup unsweetened cocoa powder; 3 cups powdered sugar; 1/3 cup milk; 1 teaspoon vanilla extract

Highlighted under: Treats from the Oven

I can’t tell you how much joy this chocolate sheet cake has brought into my life. When I first tried making it, I was amazed at how simple the recipe was while delivering such rich chocolate flavor. The cocoa gives it a deep, satisfying taste, and the ease of preparation makes it my go-to dessert for gatherings. I've made it for birthdays, holidays, and even just on a whim, and it never disappoints. The best part? It only takes 20 minutes to whip up this delicious cake!

Created by

Ottilie James

Last updated on 2026-02-15T04:05:35.884Z

When I first baked this chocolate sheet cake, I was taken aback by how rich and moist it turned out to be. I used a high-quality cocoa powder because the flavor truly shines through. The cake was a hit with my family, and it quickly became a favorite for celebrations. One detail I found crucial was not overmixing the batter, as it helps maintain that tender crumb we all love.

Every time I make this cake, I love how versatile it is. Sometimes, I add a pinch of espresso powder to deepen the chocolate flavor. Other times, I spread a simple chocolate frosting on top, or I drizzle it with a ganache. It’s always a crowd-pleaser, and the compliments keep coming!

Why You Will Love This Recipe
Decadent chocolate flavor enhanced with rich cocoa
Velvety texture that is incredibly satisfying
Quick to prepare, perfect for any gathering or occasion

The Importance of Fresh Ingredients

Using fresh ingredients is crucial for the success of this chocolate sheet cake. The quality of your cocoa powder can significantly affect the taste; I recommend using a high-quality unsweetened cocoa for the richest flavor. Fresh eggs not only provide a better taste but also contribute to a fluffier texture. When it comes to buttermilk, ensure it's not expired to achieve that perfect tangy note that balances the sweetness of the cake.

Additionally, consider the freshness of your baking powder and baking soda. Old leavening agents can lead to a denser cake that does not rise as desired. For best results, test your baking soda by adding a splash of vinegar; if it fizzes, you’re good to go!

Tips for Achieving the Perfect Frosting

The frosting on this chocolate sheet cake is just as important as the cake itself. To ensure a smooth and glossy frosting, beat the butter until it’s creamy before adding the cocoa powder. This step helps in achieving a light texture. Gradually incorporate the powdered sugar and milk to control the consistency—add more milk if the frosting is too thick or more powdered sugar if it’s too runny.

To enhance the chocolate flavor, try adding a pinch of salt or an extra splash of vanilla extract. This small addition can elevate the overall taste of the frosting, providing a well-rounded flavor that complements the cake perfectly.

Ingredients

Gather the following ingredients for your Chocolate Sheet Cake:

Cake Ingredients

1 ¾ cups all-purpose flour
2 cups granulated sugar
¾ cup unsweetened cocoa powder
1 ½ teaspoons baking soda
1 teaspoon baking powder
1 teaspoon salt
2 large eggs
1 cup buttermilk
½ cup vegetable oil
2 teaspoons vanilla extract
1 cup boiling water

Frosting Ingredients

½ cup unsalted butter, softened
⅔ cup unsweetened cocoa powder
3 cups powdered sugar
1/3 cup milk
1 teaspoon vanilla extract

Make sure you have everything ready to create this delightful cake!

Instructions

Follow these simple steps to bake the perfect chocolate sheet cake:

Preheat the Oven

Preheat your oven to 350°F (175°C) and grease a 12x17-inch sheet cake pan.

Mix Dry Ingredients

In a large mixing bowl, sift together the flour, sugar, cocoa powder, baking soda, baking powder, and salt.

Add Wet Ingredients

Add the eggs, buttermilk, vegetable oil, and vanilla to the dry ingredients. Mix until well combined.

Incorporate Boiling Water

Carefully stir in the boiling water; the batter will be thin, but that’s okay!

Bake the Cake

Pour the batter into the prepared pan and bake for 30 minutes, or until a toothpick inserted in the center comes out clean.

Prepare the Frosting

While the cake is baking, prepare the frosting by beating the softened butter and cocoa powder together. Gradually add powdered sugar and milk until smooth, then stir in vanilla.

Cool and Frost

Once the cake has cooled completely, spread the frosting evenly over the top.

Slice and serve your delicious chocolate sheet cake for everyone to enjoy!

Pro Tips

For a little extra flair, try topping the cake with chocolate shavings or fresh berries to add color and contrast to the rich chocolate.

Storing and Serving Suggestions

This cake can be stored in an airtight container at room temperature for up to three days. If you're planning to keep it for longer, consider refrigerating it, where it can last up to a week. For optimal presentation, serve it on a platter garnished with fresh berries or a sprinkle of confectioners' sugar. A scoop of vanilla ice cream on the side adds a lovely contrast to the rich chocolate flavor.

If you're serving a crowd, this recipe scales beautifully. Double the ingredients and use a larger baking sheet or pan, adjusting the baking time slightly. Keep an eye on the cake as it bakes, checking for doneness with a toothpick at around 35-40 minutes.

Ingredient Substitutions

If you find yourself out of buttermilk, don’t worry! You can easily substitute it by mixing one cup of regular milk with a tablespoon of white vinegar or lemon juice. Let it sit for about five minutes to sour. Additionally, if you need a dairy-free option, try using almond milk or coconut milk with a similar acid to achieve that tangy flavor.

Should you wish to reduce the sugar content, consider using less sugar without compromising the cake's structural integrity, especially since cocoa powder adds complexity to flavor. Alternatively, powdered coconut sugar can work well as a substitute, providing a unique taste and similar sweetness level.

Questions About Recipes

→ Can I use a different type of cocoa powder?

Absolutely! Just make sure it's unsweetened cocoa powder for the best results.

→ How should I store the cake?

Store the cake in an airtight container at room temperature for up to 3 days, or refrigerate for longer freshness.

→ Can I freeze this cake?

Yes! You can freeze the un-frosted cake for up to 3 months. Just wrap it tightly in plastic wrap.

→ Is it necessary to use buttermilk?

While buttermilk adds a nice tang and moisture, you can substitute with regular milk mixed with a teaspoon of vinegar or lemon juice.