Chocolate Sheet Cake With Frosting

Name: Chocolate Sheet Cake With Frosting
Prep time: 20 min
Cook time: 30 min
Total time: 50 min
Yield: 12 servings
Ingredients: 2 cups all-purpose flour; 2 cups granulated sugar; 3/4 cup unsweetened cocoa powder; 1 1/2 teaspoons baking powder; 1 1/2 teaspoons baking soda; 1 teaspoon salt; 2 large eggs; 1 cup buttermilk; 1 cup vegetable oil; 2 teaspoons vanilla extract; 1 cup boiling water; 1 cup unsalted butter, softened; 3/4 cup unsweetened cocoa powder; 5 cups powdered sugar; 1/2 cup milk; 2 teaspoons vanilla extract

Highlighted under: Oven Ideas

I absolutely love baking, especially when it comes to making a rich chocolate sheet cake topped with creamy frosting. This recipe is one of my favorites because it's both easy to prepare and incredibly satisfying. The cake is moist, decadent, and perfect for any occasion, whether it's a birthday party or a simple family gathering. Just wait until you see the smiles on everyone's faces when they take their first bite! Trust me; this cake will quickly become a go-to dessert in your kitchen.

Created by

Verity Langdon

Last updated on 2026-01-24T09:25:35.322Z

When I first tried making a chocolate sheet cake, I wasn't sure how it would turn out. I was amazed by the depth of flavor that the cocoa powder added—it's truly the star of the show! I discovered that using buttermilk in the batter not only makes it incredibly moist but also elevates the taste, giving it a subtle tanginess that balances perfectly with the sweetness of the frosting.

As I experimented with the frosting, I found that using unsweetened chocolate melted into the mixture created a rich and creamy texture that can’t be beat. It’s important to let the cake cool completely before frosting; this way, the frosting will adhere beautifully without melting away. This method has made all the difference in my baking journey!

Why You'll Love This Recipe
Rich chocolate flavor paired with creamy and smooth frosting
Perfect size for gatherings, making it easy to serve
Simple ingredients that create an impressive dessert

Understanding Ingredients

The foundation of this chocolate sheet cake lies in its simple yet effective ingredients. Use high-quality cocoa powder for a rich chocolate flavor; the better the cocoa, the more pronounced the chocolate notes will be in the cake. The buttermilk not only adds moisture but also contributes to a tender crumb, thanks to its acidity which helps activate the baking soda and powder effectively.

It's important to measure your dry ingredients accurately. Too much flour can lead to a dense cake, while the right balance will yield a light, fluffy texture. I recommend using the spoon-and-level method: spoon flour into your measuring cup and level it off with a knife for precision.

Baking Techniques for Success

When mixing the batter, be mindful not to overmix after incorporating wet ingredients. Beating for two minutes is ideal, but once you add boiling water, a gentle stir is sufficient to avoid developing excessive gluten, which can lead to a tough cake. The batter’s thin consistency is perfectly normal and ensures an ultra-moist finished product.

Once baked, allowing the cake to cool completely in the pan is crucial. This helps set the structure, making it easier to frost without it crumbling. If you’re in a rush, 30 minutes at room temperature typically does the trick, but if you can, let it cool even longer to enhance the texture.

Ingredients

For the Cake

2 cups all-purpose flour
2 cups granulated sugar
3/4 cup unsweetened cocoa powder
1 1/2 teaspoons baking powder
1 1/2 teaspoons baking soda
1 teaspoon salt
2 large eggs
1 cup buttermilk
1 cup vegetable oil
2 teaspoons vanilla extract
1 cup boiling water

For the Frosting

1 cup unsalted butter, softened
3/4 cup unsweetened cocoa powder
5 cups powdered sugar
1/2 cup milk
2 teaspoons vanilla extract

Instructions

Prepare the Oven and Bake the Cake

Preheat your oven to 350°F (175°C). Grease and flour a 15x10 inch baking pan. In a large mixing bowl, combine flour, sugar, cocoa powder, baking powder, baking soda, and salt. Mix well.

Mix in Wet Ingredients

Add eggs, buttermilk, vegetable oil, and vanilla extract to the dry mixture. Beat on medium speed for 2 minutes. Stir in boiling water until well blended—don’t worry, the batter will be thin.

Bake the Cake

Pour the batter into the prepared baking pan. Bake for 30 minutes or until a toothpick inserted in the center comes out clean. Allow the cake to cool completely in the pan.

Make the Frosting

In a medium bowl, beat the softened butter until creamy. Gradually add cocoa powder and powdered sugar, alternating with milk. Mix in vanilla extract until smooth.

Frost the Cake

Once the cake is completely cool, spread the frosting evenly over the top. Let it set for a bit before cutting into squares and serving.

Pro Tips

For an extra layer of flavor, try adding a dash of espresso powder to the cake batter. It will enhance the chocolate flavor without making the cake taste like coffee.

Frosting Tips

For the frosting, it's vital to ensure that your butter is adequately softened but not melted. Ideally, it should be at room temperature with a slight give when pressed. This creaminess is key for achieving that smooth, spreadable consistency without any lumps. If you find it too thick after mixing, simply add a tablespoon of milk at a time until you reach your desired consistency.

The cocoa powder should be sifted into the mixture to avoid clumps, ensuring a silky-smooth frosting. Be patient while adding the powdered sugar; doing so gradually will help you achieve a fluffy texture and prevent the mixture from turning grainy due to overworking the sugar.

Serving and Storing Suggestions

This chocolate sheet cake can be enjoyed warm or at room temperature, depending on your preference. I personally love serving it with a scoop of vanilla ice cream for a decadent treat. For a fun twist, consider adding a sprinkle of sea salt on top of the frosting to balance the sweetness and enhance the chocolate flavor.

If you plan on making this cake ahead of time, it stores beautifully in an airtight container in the refrigerator for up to a week. For longer storage, consider wrapping individual slices in plastic wrap and placing them in the freezer for up to three months; just make sure to let them thaw properly before indulging!

Questions About Recipes

→ Can I use a different pan size?

Yes, but adjust the baking time accordingly. A smaller pan will require more time; a larger one will need less.

→ How should I store the cake?

Keep the cake covered at room temperature for up to 3 days, or refrigerate it for up to a week.

→ Can I freeze the cake?

Absolutely! Wrap the cake tightly in plastic wrap and aluminum foil, and it will keep well in the freezer for up to 3 months.

→ What can I substitute for buttermilk?

You can make a substitute by mixing 1 cup of milk with 1 tablespoon of vinegar or lemon juice. Let it sit for 5-10 minutes before using.