Chocolate Sheet Cake with Chocolate Frosting is a rich, moist dessert that is perfect for birthdays, potlucks, holidays, and family gatherings. This easy homemade chocolate cake is baked in a 9×13 pan with simple pantry ingredients and topped with creamy chocolate frosting for the ultimate crowd-pleasing dessert.

We love this recipe because it is easy to make, feeds a crowd affordably, and stays soft and delicious for days. It is one of those family-tested cake recipes we make again and again for real-life celebrations and busy weekends.
Quick Glance at this Recipe
- Budget-Friendly: Made with simple pantry staples
- Family-Tested: A classic homemade chocolate cake everyone loves
- Prep Time: 15 minutes
- Bake Time: 30–35 minutes
- Method: Oven-Baked
- Freezer-Friendly: Yes
- Best For: Birthdays, potlucks, holidays, family desserts
Ingredients

- Butter – Used in both the cake and frosting for rich flavor and a soft texture. Use real butter for the best results.
- Unsweetened cocoa powder – Gives the cake and frosting their chocolate flavor. Make sure to use unsweetened cocoa powder, not hot cocoa mix.
- Water – Helps melt the butter and cocoa together to create a smooth chocolate mixture for the cake batter.
- All Purpose Flour – Gives the cake structure. Spoon and level the flour so the cake does not turn out dense.
- Granulated sugar – Sweetens the cake and helps keep it moist.
- Baking soda – Helps the cake rise and gives it a light texture.
- Salt – Balances the sweetness and enhances the chocolate flavor.
- Eggs – Help bind the cake batter together and add moisture.
- Buttermilk – Makes the cake soft, tender, and moist. You can use a homemade buttermilk substitute if needed.
- Vanilla extract – Adds warmth and brings out the chocolate flavor in both the cake and frosting.
- Confectioners Sugar – Sweetens and thickens the frosting for a smooth, creamy texture.
- Heavy Whipping Cream – Helps thin the frosting to the perfect spreadable consistency. Start with 3 tablespoons and add more if needed.
How to Make Chocolate Sheet Cake with Chocolate Frosting
For the Cake:
Step 1 – Preheat the oven to 350 degrees Fahrenheit and grease a 9×13 baking pan.

Step 2 – In a saucepan, add butter, cocoa powder and water. Stir constantly until mixture begins to boil. Remove from heat and set aside.

Step 3 – In a mixing bowl, mix together flour, sugar, baking soda and salt. Add chocolate mixture and beat well.

Step 4 – Add eggs, buttermilk and vanilla and beat well.

Step 5 – Pour into the prepared pan and bake for 30-35 minutes or until a toothpick inserted into the center comes out clean. Let cool completely before topping with the frosting.

Step 6 – Beat the butter on medium speed with a hand held mixer or stand up mixer until the butter is smooth and creamy (2-3 minutes).

Step 7 – Add in the confectioner’s sugar, cocoa powder, 3 tablespoons of the heavy cream, vanilla extract and salt. Mix on low speed until fully combined (approximately 1 minute). Check the frosting consistency and add more heavy cream if needed.
Step 8 – Spread the frosting on the cooled cake. Then the cake is ready to slice, serve and enjoy!

Tips for Success
- Let the cake cool completely before frosting so the frosting does not melt.
- Use room temperature eggs and buttermilk for smoother batter.
- Do not overbake the cake or it may dry out.
- We tested this cake in a metal 9×13 pan for the best baking results.
- For easier slicing, chill the cake slightly before serving.
Variations & Substitutions
- Let the cake cool completely before frosting so the frosting does not melt.
- Use room temperature eggs and buttermilk for smoother batter.
- Do not overbake the cake or it may dry out.
- We tested this cake in a metal 9×13 pan for the best baking results.
- For easier slicing, chill the cake slightly before serving.

Storage & Reheating Instructions
- Refrigerator – Store covered at room temperature for up to 3 days or refrigerate for up to 5 days.
- Freezer – Freeze the unfrosted or frosted cake tightly covered for up to 3 months.
- Reheating – Serve at room temperature or microwave individual slices for a few seconds for a warm dessert.
FAQs
Yes. This cake stays moist for several days and can easily be made a day in advance.
Overbaking is usually the main reason cakes become dry. Check the cake a few minutes before the bake time ends.
Yes, but homemade frosting gives the cake the best flavor and texture.
More Easy Chocolate Dessert Recipes
This Chocolate Sheet Cake with Chocolate Frosting is one of those easy desserts that always turns out delicious and is perfect for sharing. It is simple to make, feeds a crowd, and works for everything from birthdays to casual family nights.
If you try this recipe, please leave a comment or a star rating below. We love hearing how it turned out for your family and your tips may help other readers too!

Chocolate Sheet Cake with Chocolate Frosting
Ingredients
For the Cake:
- 1 cup butter
- ⅓ cup unsweetened cocoa powder
- 1 cup water
- 2 cups All Purpose Flour
- 2 cups granulated sugar
- 1 teaspoon baking soda
- ¼ teaspoon salt
- 2 large eggs
- ½ cup buttermilk
- 2 teaspoons vanilla extract
For the Frosting:
- 1 cup Unsalted Butter (softened)
- 3 cups Confectioners Sugar
- ½ cup Unsweetened Cocoa Powder
- 3-4 Tablespoons Heavy Whipping Cream
- 2 teaspoons vanilla extract
- ½ teaspoon salt
See how we calculate recipe costs.
Instructions
For the Cake:
- Preheat the oven to 350 degrees Fahrenheit and grease a 9×13 baking pan.
- In a saucepan, add 1 cup butter, ? cup unsweetened cocoa powder, and 1 cup water. Bring the mixture to a boil, stirring until combined.
- In a large mixing bowl, whisk together 2 cups all purpose flour, 2 cups granulated sugar, 1 teaspoon baking soda, and ¼ teaspoon salt.
- Pour the hot chocolate mixture over the dry ingredients and stir until combined.
- Add 2 large eggs, ½ cup buttermilk, and 2 teaspoons vanilla extract. Mix until smooth.
- Pour into the prepared pan and bake for 30-35 minutes or until a toothpick inserted into the center comes out clean. Let cool completely before topping with the frosting.
For the Frosting:
- In a large mixing bowl, beat 1 cup softened unsalted butter until smooth.
- Add 3 cups confectioners sugar, ½ cup unsweetened cocoa powder, 3-4 tablespoons heavy whipping cream, 2 teaspoons vanilla extract, and ½ teaspoon salt. Beat until the frosting is smooth and creamy.
- Spread the frosting on the cooled cake.
- Then the cake is ready to slice, serve and enjoy!




