Chocolate sheet cake is a moist and tender homemade cake with rich chocolate flavor. The velvety whipped chocolate buttercream frosting makes it perfect for chocolate lovers! This recipe can be made in a 9x13 or 13x18 pan.
Recipe summary
Flavor: Rich, sweet, and chocolatey with a tender, moist crumb. Topped with Whipped Chocolate Buttercream Frosting.
Pan size: 9x13 or 13x18
Similar to: Homemade Chocolate Cupcakes or Chocolate Layer Cake (made with the same batter recipe!)
More flavors: Vanilla Sheet Cake, Strawberry Sheet Cake, and Lemon Sheet Cake
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Ingredients and substitutions
- Wet ingredients - Granulated sugar, eggs, buttermilk, water, vegetable oil, and vanilla extract add moisture and flavor to the cake. Don't have buttermilk on hand? Add 1 tablespoon of white vinegar to a liquid measuring cup, then fill to the 1-cup line with whole milk and wait 5 minutes.
- Dry ingredients - All-purpose flour, natural cocoa powder, baking soda, baking powder, and salt balance with the dry ingredients in the recipe. Natural cocoa powder works best with the leavening agents in this recipe for a proper rise. Want to use Dutch cocoa powder anyway? Your cake will rise less in the oven, turn out darker in color, and have a milder flavor.
- Frosting ingredients (not shown above) - Unsalted butter, confectioner's sugar, natural cocoa powder, heavy cream, vanilla, and salt create a sweet, fluffy buttercream frosting. You're also welcome to use your favorite frosting recipe to top your cake.
How to make chocolate sheet cake
- Add wet ingredients to a large bowl and whisk to combine.
- Add dry ingredients to a separate bowl and whisk to remove clumps.
- Add dry ingredients, half at a time, to wet ingredients and stir until just combined.
- Pour batter into a 9x13 or 13x18 greased sheet pan. Bake cake until it pops back when pressed in the center and reaches 210F.
- Allow cake to cool completely. While cake cools, prepare frosting.
- Spread frosting with a spatula over cooled cake.
- The same amount of frosting will cover a 9x13 or 13x18 sheet cake.
Heather's top tip
To test for doneness, gently press the top of your cake. If it springs right back, it's done. If an indent is left, it needs more time. For accurate results every time, use an instant read thermometer. Cake is done when it reaches 210F in the center.
Tips and tricks
Bring eggs to room temperature - Room temperature eggs blend seamlessly into the batter without leaving and streaks or lumps. To bring eggs to room temperature, place on the countertop 30 minutes before beginning. You can also place whole eggs into a bowl and cover with warm tap water for 10 minutes.
Don't overmix the batter - Mix your dry ingredients just enough to incorporate them into the batter. Overmixing can overwork the gluten, causing your cake to turn out tough.
Don't omit or reduce any of the moisture-adding ingredients - Oil, buttermilk, eggs, and granulated sugar all do their part in ensuring your cake turns out moist and tender. Reducing, omitting, or substituting these ingredients can cause your cake to turn out dry.
Do not frost a warm cake - Buttercream frosting melts around 90 degrees Fahrenheit. Adding frosting to a hot cake will cause it to melt. Wait until your cake is completely cooled.
Storage
Homemade cakes are best served the same day they are baked for best flavor and texture. However, there are solutions if you need to make your cake a few days (or weeks) ahead of time.
Room temperature - Frosted cake can be stored in a tightly sealed container (or wrapped well with foil) at room temperature for 2-3 days, but will begin to dry out over time.
Freezing - Cake and frosting freezes and thaws beautifully, maintaining its original texture and moisture just like the day it was baked. Unfrosted or frosted cake can be frozen for up to two months. To store a frosted cake, first freeze for an hour, unwrapped, until firm. Gently wrap in plastic and store in a tightly sealed container for up to 2 months. Thaw your cake in the refrigerator overnight, then bring to room temperature 30-60 minutes before serving.
Refrigerating - I do not recommend this option unless you live in a hot or tropical climate. Refrigerators are a low humidity environment and dry out cake faster than storing at room temperature or freezing. Unfrosted or frosted cake can be refrigerated for 3 to 4 days if needed. Wrap unfrosted cake in plastic and store in a sealed container. Bring to room temperature 30-60 minutes before serving.
Hot climates - Buttercream frosting should not sit out in the sun or a hot room for extended periods of time because it melts at about 90 degrees Fahrenheit. If it's summertime or you live in a tropical climate, you may need to store your buttercream frosted cake in the refrigerator until 30 minutes before serving to prevent melting.
Frequently asked questions
This recipe works in three different sizes: a 9x13 baking pan (with 2 inch tall sides), two 9-inch round cake pans, or a 13x18 half sheet pan (with 1 inch sides).
Both the 9x13 and 13x18 sheet cakes can remain in the pan after baking. Simply frost, slice, and serve! To make this as a layer cake, follow my recipe for chocolate layer cake.
Here are the cake pans I recommend for making vanilla sheet cake:
- Nordic Ware Classic Metal 9x13 Covered Cake Pan
- Natural Aluminum Nordic Ware Commercial Baker's Half Sheet (2 Pack)
- Nordic Ware 9" Round Natural Aluminum Cake Pans (2 Pack)
Buttercream frosting is a traditional, very sweet frosting that is often found in grocery store bakeries and on birthday cakes. It is popular because it's easy to prepare with just two main ingredients - butter and confectioner's sugar. Since buttercream includes so few ingredients, it is not easy to alter to make less sweet. Adding less sugar makes the frosting too soft to pipe and also tastes like sweetened butter.
Instead, I'd suggest making a less sweet frosting recipe. All of these frostings are less sweet that buttercream: ermine frosting, chocolate ermine frosting, homemade whipped cream, chocolate Italian meringue buttercream, and chocolate Swiss meringue buttercream.
Baked goods can be frosted with buttercream the day before an event and left at room temperature in a sealed container. Keep in mind that butter (and in turn, buttercream) melts around 90 to 95 degrees Fahrenheit.
If your location is nearing this temperature, I'd recommend refrigerating your baked goods until an hour before you're ready to serve them. Refrigerating your frosted baked goods for a short amount of time will not hurt them. However, you will want to give them some time to come to room temperature before serving.
Here's a fantastic article about how frosting holds up to heat: The Best Cake Frosting For Hot Weather
Yes, this frosting pipes beautifully and can be used for rosettes, borders, and topping cupcakes.
Check your cake for doneness by jiggling the pan - if it moves, it's not done yet. If your cake isn't jiggly in the center, gently press onto the top with a finger. If an indent is left, it needs more time. If it pops right back, your cake is done. Use an instant read thermometer for most accurate results. Cake is done when it reaches 210F in the center.
This recipe can be sliced to serve as many as 30-40 people with small slices (think wedding cake slices). Larger squares will yield about 16 slices.
Troubleshooting
Baked goods can turn out dry for a few reasons:
- Baking too long.
- Adding too many dry ingredients.
- Adding too few wet ingredients.
It's important to follow the recipe exactly, including the measurements and exact ingredients listed. I recommend using an instant-read thermometer to make sure your cake doesn't get overbaked in the oven.
This is a baker's secret that's optional but effective! Brush simple syrup over your cake before frosting. A layer of simple syrup helps keep the cake moist for longer. Simple syrup is a 1:1 ratio of water and granulated sugar, brought to a boil on the stove top until dissolved, then cooled to room temperature. I'd suggest about ¼ cup or more for this size cake.
Cake can turn out dense from expired leavening, overmixing the wet and dry ingredients (this overworks the gluten) or adding extra wet ingredients (like adding sour cream or applesauce to make cake "extra moist"). If the balance of wet and dry ingredients is off, this can cause a change in texture, preventing your cake from rising properly in the oven.
Sinking can happen for many reasons. Overmixing the batter (which adds extra air that's released during baking), underbaking, using expired leavening, using the wrong leavening, or accidentally doubling the leavening can all cause your cake to sink in the middle.
Recommended
📖 Recipe
Chocolate Sheet Cake
Ingredients
Chocolate cake
- 1 ¾ cups (210 g) all-purpose flour
- ¾ cup (63 g) natural cocoa powder
- 2 teaspoons baking soda
- 1 teaspoon baking powder
- ½ teaspoon salt
- 1 ¾ cups (345 g) granulated sugar
- 3 large eggs, room temperature
- 1 cup (227 g) buttermilk
- 1 cup (226 g) warm water
- ½ cup (100 g) vegetable oil
- 2 teaspoons vanilla extract
Whipped chocolate buttercream frosting
- 1 cup (227 g) unsalted butter, room temperature
- 3 cups (342 g) confectioner's sugar
- ½ cup (42 g) natural cocoa powder
- ⅓ cup (75 g) heavy cream, cold
- 2 teaspoons vanilla extract
- ¼ teaspoon salt
Instructions
Cake
- Preheat oven to 350℉. Generously grease a 9x13 or 13x18 inch baking pan and set aside.
- In a bowl, add flour, cocoa powder, baking soda, baking powder, and salt. Sift or whisk to remove clumps. Set aside.
- In a large bowl, add granulated sugar, eggs, buttermilk, warm water, vegetable oil, and vanilla extract. Whisk or stir until evenly incorporated.
- Add half of the dry ingredients to the wet ingredients. Gently stir until just combined. Add remaining dry ingredients and stir until just combined (do not overmix). Batter should look thin and a little bubbly.
- Pour batter into prepared baking pan.
- 9x13 baking pan: 32-38 minutes13x18 half sheet pan: 18-20 minutesBake your cake using the time frames above as a reference. To test for doneness, gently press into the center of your cake with a finger. If it bounces back, it's done. If it leaves an indent, the cake needs more time. Use an instant read thermometer for exact results. Cake is done when it reaches 210F in the center.
- Remove cake from oven and allow to cool completely in the pan on a wire cooling rack.
Frosting
- In a large bowl, add room temperature butter. Using a hand mixer or stand mixer, beat until creamy (about a minute). Gradually add confectioner's sugar and cocoa powder and mix slowly until ingredients are fully combined. Then, whip at high speed for about 2-3 minutes, or until light and fluffy.
- Add heavy cream, vanilla extract, and salt. Whip for an additional 2-3 minutes, or until light and fluffy. Add additional heavy cream as needed to reach desired consistency.
- Spread frosting in an even layer onto cooled cake. Optionally, add sprinkles before frosting crusts.
Equipment Recommendations
Notes
- Servings: Sheet cake can be sliced to serve up to 24 guests.
- Science: Baking is an exact science. I do not recommend substituting any ingredients. The oil, buttermilk, eggs, and sugar keep your cake moist - substituting any of these ingredients can change the texture and make your cake dry.
- Storage: Unfrosted or frosted cake will keep in a sealed container at room temperature for 2-3 days, in the refrigerator for 3-4 days, or frozen for up to 2 months. If refrigerating or freezing unfrosted cake layers, wrap tightly in plastic and place in a tightly sealed container. Thaw overnight in the refrigerator, then bring to room temperature for an hour before serving.
- Tips: Be sure to check out my 10 tips for baking cake, based on reader comments and questions!
Oh Heather, it was absolutely beautiful. I had to double the recipe as I was feeding up to 40 people. I wasn't certain how much coconut to add, but once I looked in the cupboard it made my decision as I only had one cup left. I warmed up the cake and served with a chocolate ganache and ice cream. I had comments that this was the best desert ever.
So glad to hear the cake was a success, Denise!
Can I add coconut to the chocolate sheet cake, I was wanting to make this into a desert by serving it with a chocolate sauce.
I haven't tried adding coconut to this recipe, but it should work! Let us know how it goes if you give it a try.
The directions call for eggs,. But the ingredients don't have any listed. How many?? I hope you comment soon because I started making it.
Hi Miranda, eggs are the 7th ingredient on the list "3 large eggs, room temperature".
Can I use the vanilla sheet cake and the chocolate sheet cake to make a marble cake?
This should work, but I haven't personally tried it myself. If you give it a try, let us know how it goes!