An easy, rich 9×13 Chocolate Cake Recipe made in one bowl with minimal ingredients. Based on my popular best chocolate cake recipe, it is tender, moist, and delicious!
This is the easiest 9×13 chocolate cake recipe I’ve ever made. From my Best Chocolate Cake that everyone loves, I’ve made the cake even easier and sized for a 9×13 sheet cake!
I love this easy 9×13 size cake for taking to potlucks, tailgating, baking, taking to friends or neighbors, and for making a quick and easy cake! It transports beautifully in the baking dish and I love that I don’t have to worry about a cake slipping or sliding on a cake plate! Another favorite version you may enjoy is my Chocolate Loaf Cake. So easy!
I originally shared this recipe in 2014 and have updated it to include the metric conversion to grams as well as updated the recipe sizing to make for a thicker cake based on reader feedback.
Best Chocolate Cake (9×13 Recipe)
What Makes a Chocolate Cake Moist?
This cake recipe includes the perfect ratio of oil, milk, and boiling water to make it moist without having to use melted chocolate. The combination of the fat, protein, and water temperature produces a moist and tender crumb.
Ingredients for Easy 9×13 Chocolate Cake
Be sure to see the recipe card below for the full listing of ingredients, instructions, notes, and estimated nutritional information.
- all-purpose flour – I recommend using a good quality all-purpose flour that works well in baking. You can also substitute with cake flour if needed.
- sugar – You’ll use granulated sugar.
- unsweetened cocoa powder – I use unsweetened cocoa powder.
- baking powder – used to leaven the cake.
- baking soda – also used to help the cake rise.
- kosher salt – I use Diamond Crystal Kosher Salt. If you substitute with Morton’s Kosher salt, fine sea salt, or table salt, you will only need half the amount of the salt called for in the recipe.
- espresso powder – Espresso powder enhances the flavor of chocolate in recipes. The amount used in this cake does not give a coffee flavor to the cake or leave a bitter aftertaste that you may get from using brewed coffee or instant coffee in the cake batter. You can use homemade espresso powder or your favorite store-bought. Many grocery stores now carry it. You can also omit it if you prefer or are unable to find it.
- milk – You can use buttermilk, whole milk, or coconut milk.
- vegetable oil – the oil is key for a moist chocolate cake.
- egg – Make sure that your egg is at room temperature so that it combines more easily into the cake batter.
- vanilla extract – Use good quality vanilla extract.
- boiling water – helps release the chocolate flavor in the recipe. Please don’t skip it!
Chocolate Buttercream
I scaled the chocolate buttercream frosting to work perfectly in a 9×13 baking dish. The cake still rises nicely so that you have a lovely, thick cake that you then top with a generous amount of silky chocolate buttercream.
Chocolate Buttercream Ingredients: you’ll need butter, cocoa powder, confectioner’s sugar, milk, vanilla extract, and espresso powder.
Step-by-Step Instructions
Prep. Preheat the oven and prep the baking dish.
Make the cake batter. Add the flour, sugar, cocoa powder, baking powder, baking soda, salt, and espresso powder to a large mixing bowl. Whisk through to combine. Add the milk, oil, eggs, and vanilla extract to the flour mixture and combine. Carefully stir in the boiling water until well combined. The cake batter will be thin.
Bake the cake. Pour the cake batter into the prepared 9×13 baking dish. Bake for 30 to 40 minutes, until a toothpick inserted in the center comes out clean. Remove from the oven and cool the baking dish on a wire rack until cooled completely.
Make the frosting. Meanwhile, add cocoa powder to a large mixing bowl. Whisk to break up any large lumps in the cocoa powder. Add the butter and using a hand mixer, cream the butter and cocoa powder together until well combined. Add confectioner’s sugar to another large bowl and whisk through it. Add the confectioner’s sugar and milk to the cocoa mixture by adding 1 cup of confectioner’s sugar followed by about a tablespoon of milk. After combining each addition, turn the mixer onto a high speed for about a minute. Repeat until all sugar and milk have been added. Add vanilla extract and espresso powder and combine well. Mix until the frosting is silky and smooth.
I put together a quick video to show you just how easy the cake is to mix together. Seriously, it’s the easiest and most delicious cake ever, I think! 🙂
As with any 9×13 cake recipe, you can cut the pieces as generously or as conservatively as you please. You can cut the cake into 2-inch x 2-inch pieces for 24 servings or 2-inch x 3-inch pieces for 18 servings.
Here’s my Easy 9×13 Chocolate Cake Recipe. I think you are going to love how simple it is!
Best Chocolate Cake Recipe (9×13 Recipe)
Ingredients
Chocolate Cake Recipe (9×13 Recipe)
- 2 cups (240 g) all-purpose flour
- 2 cups (396 g) granulated sugar
- 3/4 cup (63 g) unsweetened cocoa powder
- 2 teaspoons (8 g) baking powder
- 1 1/2 teaspoons (9 g) baking soda
- 1 teaspoon (2.8 g) kosher salt
- 1 teaspoon (2.3 g) espresso powder
- 1 cup (227 g) buttermilk, whole milk, or coconut milk
- 1/2 cup (99 g) vegetable oil
- 2 large (100 g) eggs
- 2 teaspoons (9.4 g) vanilla extract
- 1 cup (227 g) boiling water
Chocolate Buttercream Frosting (9×13 Recipe)
- 1/2 cup (42 g) unsweetened cocoa powder
- 3/4 cup (169.5 g) butter, softened
- 2 1/2 cups (283.7 g) confectioner’s sugar
- 1/4 cup (56.7 g) milk
- 1 teaspoon (4.7 g) vanilla extract
- 1/4 teaspoon (0.57 g) espresso powder
Instructions
- Preheat oven to 350º F. Prepare one 9×13 baking dish by spraying with baking spray or buttering and lightly flouring.
- Whisk together flour, sugar, cocoa, baking powder, baking soda, salt and espresso powder to a large mixing bowl.
- Add milk, vegetable oil, eggs, and vanilla to flour mixture and mix together until well combined. Carefully stir the boiling water into the cake batter and pour into the prepared 9×13 dish.
- Bake for 30-35 minutes, until a toothpick or cake tester inserted in the center comes out clean. You can follow my tips for how to tell when your cake is done.
- Remove from the oven and allow to cool completely.
Chocolate Buttercream Frosting (9×13 Recipe)
- Add cocoa to a large bowl or bowl of stand mixer. Whisk through to remove any lumps.
- Add the butter and cream together butter and cocoa powder until well-combined.
- Add sugar and milk to cocoa mixture by adding 1 cup of sugar followed by about a tablespoon of milk. After each addition has been combined, turn mixer onto a high speed for about a minute. Repeat until all sugar and milk have been added.
- Add vanilla extract and espresso powder and combine well.
- If frosting appears too dry, add more milk, a tablespoon at a time until it reaches the right consistency. If it appears to wet and does not hold its form, add more confectioner’s sugar, a tablespoon at a time until it reaches the right consistency.
- Spread the frosting on top of the cooled cake. Cover and keep on the counter for up to 3 days for best taste.
Notes
1 cup granulated sugar
1/2 cup unsweetened cocoa powder
1 teaspoon baking powder
1/2 teaspoon baking soda
1/2 teaspoon kosher salt
1/2 teaspoon espresso powder
1/2 cup whole milk, buttermilk, or coconut milk
1/4 cup vegetable oil
1 large egg
1/2 teaspoon vanilla extract
1/2 cup boiling water
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
Enjoy!
Robyn xo
We absolutely loved this! And thought the sizing was perfect for a 9×13 pan. Thanks so much for a great recipe!
I’ve read both the round cake recipe and the 9×13 and I’m just wondering why you don’t use the mixer for the 9×13?
Thanks!
Hello Robyn,I want to make your cake today for my neighbour,he was diagnosed yesterday with Motor Neurones Decease and asked me to make him a chocolate cake, I have chosen your chocolate cake recipe but would like to make it in a 2lb loaf tin,for ease of cutting etc for him,could you give me some idea of cooking times etc,
Thank you regards Delia
Hi Delia –
Please give my best regards to your neighbor – I am sorry he is not well and hope he is ok.
I’ve not made this particular cake in a loaf tin, so I can’t advise how to change the recipe. I have, however, written this cake recipe for my Best Chocolate Cake 9×13 Pan in case this would work better for you.
Thanks! xo
Hi Robyn! 🙂
I was wondering if I could use this recipe for a 9 inch round pan, since I only have round pans and just want to make a single layer cake.
This really was a great cake and frosting. I had just had two bakery cakes brought home to me (made the cake before I knew they were coming) and this one out-shined them both.
Thanks so much Shaylinn! I’m thrilled that you enjoyed it! xo
Hi Robyn,
I made this cake for my daughter’s bday ( round 9 inch) and it was amazing. everyone loved it and asked for the recipe.
I need to make this for a larger group now. Can you please tell me the adjustments I need to make for a half sheet cake?
Thanks for this lovely recipe.
Regards
Lavanya
I’m so happy you enjoyed the cake for your daughter’s birthday. Look at the recipe Best Chocolate Cake with Fudge Icing for instructions on how to make this cake in a half sheet pan. xo
Hello!
I’ve made the original recipe several times now and love it. For a birthday party this weekend, I wanted to make a 9×13 version of the cake so I checked this out to see if there were any changes for baking temp/time. When I read this recipe, I was confused by the fact that it’s written to make only half as much batter (and that some of the ratios were changed). I can see why there are so many comments about the cake turning out flat!! It’s not because of old ingredients, but because there is only half as much batter in this recipe as there should be. Two 9″ round pans together only hold slightly more volume than a 9×13″ pan (less than 10% difference). (Comparing the surface areas gives you about 127 sq inches for the two round pans, and 117 sq inches for the rectangular one.) Pretty close!
So instead of using this recipe, I just made the original cake recipe as written for 2 round pans, and poured the batter into my greased 9×13″ pan. Baked it at 350 for about 35 minutes. Turned out perfect! Easy peasy.
Thought I would share in case that’s helpful for anyone! You can safely go ahead and just use the original recipe. 🙂
I wish I had read this before putting mine in the oven! 🙁 so flat!
Hi Liserb –
I’m sorry yours turned out flat – it should not have been. I make this often and don’t have that problem. I can’t be sure what happened, but could it be possible that the baking powder or baking soda were not fresh? Sometimes that can keep a cake from rising as it should.
Thanks!
Thanks, this really helped. I was having the same doubt as I wanted to make one 9X13 for a big group and didn’t understand whether to make the original recipe or the scaled down version.
I hope you enjoy the cake! You can see the thickness of my recipe in my video and in my pictures. I prefer it this thickness, but if you like it thicker, you can certainly make more batter as discussed here.
Either way, it is a delicious cake and I hope you like it!
Thanks so much! xo
I tried the recipe for the 9×13 and it was flat. It was Not because of old ingredients. I made it again using the original cake recipe and baked it in a 9×13 pan. It turned out perfectly. I used the icing recipe for the scaled down version. This is the correct balance of cake and icing.
We love love this chocolate cake! And we are chocolate freaks!
Oh I’m so glad you love it! Thanks so much! xo
Made this cake last night for company I did not have instant expresso But didnt matter everyone had 2 servings was delish! My boys are not big on cake and frosting and they had seconds also This will be my new go to cake recipe can’t wait to make it again and will try with instant espresso!
Great, Marcelle! So happy you all liked it! Thanks so much!
The cake was good, but the frosting is amazing! Thanks for a quick and easy recipe. BTW – My cake was a bit flat too but my baking soda could stand to be replaced.