Moist Chocolate Sheet Cake With Chocolate Frosting

Name: Moist Chocolate Sheet Cake With Chocolate Frosting
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 powder; 1 ½ teaspoons baking soda; 1 teaspoon salt; 2 large eggs; 1 cup whole milk; 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 whole milk; 1 teaspoon vanilla extract

Highlighted under: Sweet Inspirations

I can never resist a slice of Moist Chocolate Sheet Cake With Chocolate Frosting. This recipe has quickly become a favorite in our household, and I love how easy it is to prepare. The cake is incredibly moist, thanks to the blend of ingredients that create a rich experience with every bite. The frosting is the cherry on top, bringing a sweet and creamy finish that elevates the cake further. Whether it's for a birthday or a casual weekend treat, this cake always satisfies my chocolate cravings.

Created by

Brielle Thompson

Last updated on 2026-01-24T12:22:11.361Z

When I first attempted to bake this cake, I was nervous about achieving the perfect balance between moistness and consistency. I experimented with different ratios of flour and liquid until I found the ideal mix that resulted in an incredibly delicious cake. Using high-quality cocoa powder also makes a significant difference in flavor.

Frosting the cake was a joy; I learned that letting the cake cool completely before applying the frosting prevents melting and helps to achieve a beautiful finish. The end result is always a fluffy, rich, and comforting dessert that everyone raves about!

Why You'll Love This Recipe
Rich chocolate flavor paired with creamy chocolate frosting
Extremely moist texture that keeps every slice fresh
Perfect for any occasion or just to satisfy your chocolate cravings

Understanding the Ingredients

Each ingredient in this Moist Chocolate Sheet Cake plays a crucial role in achieving its signature moistness and rich flavor. The combination of all-purpose flour and granulated sugar creates the perfect structure, while the unsweetened cocoa powder ensures a deep chocolate taste. The use of both baking powder and baking soda provides the necessary leavening, allowing the cake to rise beautifully without becoming dry. Pay close attention to the quality of cocoa powder; using a high-quality brand can significantly enhance the chocolate flavor of your cake.

The addition of boiling water might seem unusual, but it is a key step. This technique not only helps dissolve the cocoa powder and sugar, enhancing the chocolate flavor profile, but it also contributes to the moist texture by activating the cocoa and creating steam during baking. If you're looking to switch up the flavors, consider using strong brewed coffee instead of boiling water for an even more intense chocolate experience.

Perfecting the Frosting

Frosting can make or break a dessert, and this chocolate frosting is the perfect complement to the cake. Start by ensuring your unsalted butter is at room temperature; this will help achieve a creamy consistency. When mixing, add cocoa powder gradually—you want it to blend well without any lumps. If the frosting ends up too thick, you can easily adjust the consistency by adding a splash more milk until it reaches your desired spreadability.

For an added layer of decadence, consider incorporating a pinch of sea salt into the frosting. This slight contrast can elevate the sweetness and play off the rich chocolate flavors beautifully. To store leftover frosting, place it in an airtight container in the fridge; it can last up to a week. Just be sure to let it soften at room temperature before reusing, and whip it briefly to restore the fluffy texture.

Serving and Storing

Once your cake is frosted and ready to serve, consider cutting it into squares rather than traditional slices—this not only makes for easier serving at gatherings but also creates lovely bite-sized pieces perfect for parties or coffee breaks. For a fun twist, you could even top each square with a dollop of whipped cream or a sprinkle of chocolate shavings before serving.

If you're planning to make this cake ahead of time, it stores beautifully. Keep the cake covered at room temperature for up to three days. For longer storage, you can freeze individual pieces by wrapping them tightly in plastic wrap and placing them in a freezer-safe container. Just let them thaw in the fridge overnight before serving, and they will taste as delightful as the day they were made.

Ingredients

For the Cake

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

For the Frosting

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

Preparation Steps

Instructions

Prepare the Oven and Pan

Preheat your oven to 350°F (175°C) and grease a 13x9 inch baking pan.

Mix Dry Ingredients

In a large bowl, combine flour, sugar, cocoa powder, baking powder, baking soda, and salt. Whisk until well combined.

Combine Wet Ingredients

Add eggs, milk, oil, and vanilla to the dry ingredients and mix on medium speed for 2 minutes, then carefully stir in boiling water.

Bake the Cake

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

Prepare the Frosting

While the cake is baking, beat butter until creamy, add cocoa powder, and mix well. Gradually add powdered sugar, alternating with milk, and vanilla until the frosting is rich and fluffy.

Frost the Cake

Let the cake cool completely in the pan. Once cooled, spread the chocolate frosting evenly over the top.

Enjoy!

Pro Tips

For an extra touch, try adding chocolate chips to the batter or sprinkle some on top of the frosting for decoration.

Cake Baking Troubleshooting

Baking can sometimes come with unforeseen challenges, so it's good to know how to handle them. If your cake domes in the center instead of baking flat, it may be due to an overly hot oven or excess leavening agents. Always check your oven's temperature with an oven thermometer for accuracy. If your cake ends up dry, it likely baked too long; keep an eye on it towards the end of the baking time and perform the toothpick test for doneness.

In the event that you notice the edges of your cake darkening too quickly, you can place a piece of aluminum foil over the pan during the last few minutes of baking. This will protect the edges while allowing the center to cook properly without burning.

Scaling the Recipe

If you're looking to make a larger batch of this cake for a big event, it's entirely possible to double the recipe. Just be diligent about using a larger baking pan—consider a 17x11 inch sheet pan for double the ingredients. For a smaller gathering, you could also halve the recipe and use an 8-inch square pan, adjusting the baking time down to about 25 minutes.

When scaling the recipe, keep in mind that all ingredients should be adjusted accordingly. Pay careful attention to the baking time, as different sized pans may require slight adjustments. Always check for doneness using a toothpick to avoid over or under baking.

Flavor Variations

For those who want to experiment with flavors, try incorporating add-ins like chocolate chips or chopped nuts into the batter for additional texture. A tablespoon of instant espresso powder can also enhance the chocolate flavor without adding any coffee taste, making it richer and more complex.

If you're in the mood for a change from chocolate, consider a simple swap of flavors. Use vanilla extract instead of chocolate in the frosting to create a vanilla sheet cake, or try adding a hint of mint extract for a refreshing mint chocolate variation. This versatility allows you to enjoy this cake in different delicious ways, keeping it exciting for every occasion.

Questions About Recipes

→ Can I use another type of flour?

You can try using gluten-free flour, but the texture may vary.

→ How do I store leftovers?

Store the cake in an airtight container at room temperature for up to 3 days.

→ Can I freeze the cake?

Yes, you can freeze the cake without frosting for up to 2 months. Just wrap it tightly in plastic wrap.

→ What can I substitute for eggs?

You can use unsweetened applesauce or flaxseed meal mixed with water as an egg substitute.