This classic chocolate sheet cake is soft, rich, and topped with a fluffy chocolate buttercream — an easy 9×13 cake that’s perfect for birthdays, celebrations, or anytime you need a reliable chocolate cake.
If you’re looking for a classic chocolate sheet cake that’s simple to make and consistently delicious, this is one to keep on repeat. It bakes in a standard 9×13 pan, making it ideal for birthdays, gatherings, or anytime you want an easy chocolate cake without stacking layers.
Instead of relying only on cocoa powder, this recipe uses melted chocolate in the batter for a deeper, more balanced chocolate flavor. Buttermilk and sour cream keep the crumb soft and fluffy, while a smooth chocolate buttercream adds the perfect rich finish.
It’s the kind of dependable chocolate cake that works for celebrations but is easy enough to make just because.
Why You’ll Love This Chocolate Sheet Cake Recipe
- Classic chocolate flavor: Melted chocolate in the batter gives this cake a rich, well-rounded flavor that feels a little more special than cocoa-only cakes.
- Soft, fluffy texture: Buttermilk and sour cream create a tender crumb that stays moist without being dense or fudgy.
- Easy 9×13 cake: No layering, no complicated decorating — just bake, frost, and serve.
- Rich chocolate buttercream: The frosting is smooth, creamy, and classic — perfect for spreading and great for celebrations.
- Reliable and versatile: Dress it up with sprinkles for birthdays, keep it simple for everyday baking, or serve it as a crowd-friendly dessert.
Key Ingredients
- Unsweetened chocolate – Melted chocolate gives this cake a deeper, more balanced chocolate flavor compared to cakes made with cocoa powder alone. It’s the main reason this cake tastes especially rich without being heavy.
- Buttermilk – Adds tanginess and helps create a soft, tender crumb. It also enhances the chocolate flavor and keeps the cake moist.
- Sour cream – Works alongside the buttermilk to create a fluffy texture and adds richness without making the cake dense.
- Brown sugar – A small amount of brown sugar adds moisture and a subtle depth of flavor that complements the chocolate.
- Butter – Provides structure and classic cake flavor. Using butter instead of oil gives the cake a more traditional sheet cake texture.
- Cocoa powder (frosting) – While the cake relies on melted chocolate, the buttercream uses cocoa powder for a smooth, chocolatey frosting that spreads easily.
The full list of ingredients and measurements is in the recipe card below.
Is This a Texas Sheet Cake?
No — while both are baked in a rectangular pan, this recipe is a classic chocolate sheet cake rather than a Texas sheet cake.
Texas sheet cake is typically thinner, made with cocoa powder, and topped with a warm poured frosting that spreads over the cake while it’s still hot. This version is thicker, uses melted chocolate in the batter for deeper flavor, and is finished with a fluffy chocolate buttercream.
If you’re looking for that thinner cake with a pour-over frosting, you can try my Texas sheet cake recipe. If you want a soft, classic chocolate cake with a rich buttercream, this is the one to make.
How to Make Chocolate Sheet Cake
Prepare the pan well.
Greasing and lining the pan makes it easier to lift the cake out for clean slicing, but you can skip the parchment if you plan to serve it directly from the pan.
Whisk the dry ingredients first.
Mixing these separately helps distribute the leavening evenly so the cake bakes with a consistent texture.
Cream the butter and sugars until fluffy.
This step creates structure and helps give the cake its soft, fluffy crumb rather than a dense texture.
Add the melted chocolate after the eggs.
Incorporating the chocolate at this stage allows it to blend smoothly into the batter while keeping the mixture stable and well-emulsified.
Alternate the dry ingredients and buttermilk.
This keeps the batter smooth and prevents over-mixing, which can make the cake tough.
Stir in the sour cream at the end.
Adding it last helps maintain a tender crumb and gives the cake its rich but still light texture.
Bake just until done.
The center should spring back lightly and a tester should come out clean or with a few moist crumbs. Over-baking is the quickest way to lose softness.
Cool completely before frosting.
This ensures the buttercream spreads smoothly and keeps its light texture instead of melting into the cake.
Make the frosting.
Beat the butter until very smooth before adding the dry ingredients to help create a fluffy buttercream that spreads easily and complements the soft cake.
Tips for Success
- Use good quality chocolate. Because the cake relies on melted chocolate for most of its flavor, the quality you use makes a noticeable difference.
- Let the melted chocolate cool slightly. If it’s too warm, it can affect the butter mixture and change the batter’s texture.
- Don’t rush the creaming step. Fully creaming the butter and sugars helps create the soft, fluffy crumb that defines this cake.
- Avoid over-mixing once the flour is added. Mixing just until combined keeps the cake tender rather than dense.
- Watch the bake time closely. This cake stays soft when baked just to doneness. A few moist crumbs on a tester are ideal.
- Frost when completely cool. This helps the buttercream stay light and spread smoothly without melting into the cake.
Variations and Serving Ideas
- Add sprinkles for celebrations. This cake is perfect for birthdays and parties. Sprinkles instantly turn it into a festive dessert.
- Serve straight from the pan or lift it out. Frost and serve in the pan for an easy everyday cake, or lift it out for cleaner slices and a more polished presentation.
- Try a different frosting. Cream cheese frosting, whipped chocolate frosting, or even a simple chocolate glaze all work well here.
- Keep it simple. A light dusting of powdered sugar or a thin swirl of frosting makes this a great everyday chocolate cake.
- Dress it up for serving. Pair slices with whipped cream, berries, or a scoop of vanilla ice cream for an easy plated dessert.
How to Store
Room temperature: Keep the cake in an airtight container. It should keep at room temperature up to 3 days. Refrigerating the cake will extend its shelf life by a couple of days, but it’s likely to become dry.
Freezer: The unfrosted cake can be wrapped well in plastic wrap and again in aluminum foil. To freeze the frosted cake, place the cake or individual slices on a rimmed baking sheet. Place in the freezer until the frosting has frozen solid. That will usually take 3 or 4 hours. Then, wrap the cake well in plastic wrap, and then wrap again in aluminum foil or place in a freezer-safe container that’s airtight. Properly stored, the cake should last up to 3 months in the freezer. Thaw at room temperature.
A Classic for Any Occasion
This chocolate sheet cake is the kind of recipe that’s easy to return to again and again. It’s simple to make, reliably soft and fluffy, and versatile enough for everything from birthdays to casual weeknight baking.
Using melted chocolate gives the cake a deeper flavor while keeping the texture light, and the smooth chocolate buttercream makes it feel just a little more special without adding extra effort.
Whether you dress it up for a celebration or keep it simple, this is a classic chocolate cake that fits just about any occasion.
More Sheet Cake Recipes
Chocolate Sheet Cake
Ingredients
For the cake:
- 2 cups (240 g) all-purpose flour
- 1 teaspoon baking soda
- ½ teaspoon salt
- 1 cup (226 g) unsalted butter, softened
- 1 ¼ cups (250 g) granulated sugar
- ¾ cup (150 g) firmly packed light brown sugar
- 4 large eggs
- 6 ounces (170 g) unsweetened chocolate, melted and slightly cooled
- 1 teaspoon vanilla extract
- ¾ cup (180 ml) buttermilk
- ¼ cup (56 g) sour cream
For the frosting:
- 1 cup (226 g) unsalted butter, softened
- 3 ½ cups (385 g) confectioners' sugar
- ½ cup (42 g) unsweetened cocoa powder
- ¼ cup (60 ml) heavy cream
- 1 ½ teaspoons vanilla extract
- ¼ teaspoon salt
- sprinkles, optional for garnishing the frosted cake
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Instructions
To make the cake:
- Preheat the oven to 350°F (175°C). Grease a 9" x 13" x 2" baking pan. If you like, line the pan with parchment paper and grease the paper.
- Whisk together the flour, baking soda, and salt. Set aside.
- Using an electric mixer on medium speed, beat the butter, sugar, and brown sugar until light and fluffy. Add the eggs, one at a time, mixing well after each addition.
- Add the melted chocoalte and vanilla, and mix until combined.
- Reduce the mixer speed to low. Add the flour mixture in three portions, alternating with two portions of the buttermilk. Mix in the sour cream. Don't over-mix; only mix just until combined.
- Transfer the batter to the prepared pan, and spread evenly. Tap the pan gently on the countertop a few times to dislodge air bubbles.
- Bake 35 to 40 minutes, or until a pick inserted into the center of the cake comes out clean.
- Place the pan on a wire rack, and allow the cake to cool completely before frosting.
To make the frosting:
- Using an electric mixer on medium speed, beat the butter until light and fluffy.
- Reduce the mixer speed to low. Gradually add the confectioners' sugar, cocoa powder, cream, vanilla, and salt. Mix until thoroughly combined and fluffy. If needed, add a small amount of cream to thin the frosting or confectioners' sugar to thicken the frosting.
- Spread the frosting over the top of the cooled cake. Decorate with sprinkles.
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Notes
- Frosting in the pan vs removing: You can frost and serve the cake directly in the pan for an easy option, or lift it out using parchment for cleaner slices.
- Parchment is helpful but optional: Lining the pan makes removal easier, but the cake works perfectly well served from the pan without it.
- Make ahead: The unfrosted cake can be baked a day in advance, tightly covered, and frosted before serving.
- Storage: Keep the cake in an airtight container at room temperature up to 3 days.
- Freezing: The cake freezes well, frosted or unfrosted. Wrap tightly and freeze for up to 3 months, then thaw at room temperature.
