This chocolate sheet cake is super rich & moist, yet simple and easy to make. Made up of a soft, decadent chocolate cake that is packed with chocolate flavor and topped with a ridiculously good (yet easy to make) chocolate fudge frosting, I guarantee this chocolate sheet cake will become a family favorite!

Why You’ll Love This Chocolate Sheet Cake
When it comes to chocolate cake, it needs to be rich and super chocolatey, moist in texture and paired with a delicious frosting. This chocolate sheet cake has all those elements (like my popular rich chocolate cake recipe – except this one is easier to make)! Let’s dive a little deeper into each element 🙂
Rich Chocolate Flavor
I wanted this sheet cake to be easy to make without compromising on flavor. I made sure to use heaps of cocoa powder to pack in the chocolate flavor, and balanced it out with both soft light brown sugar and regular granulated sugar. Brown sugar adds additional moisture and flavor to the cake which is why I love using it in this recipe.
To amplify the cocoa flavor, I also used hot coffee in this recipe. Coffee is used in chocolate flavored recipes to amp up the chocolate flavor (without it tasting like coffee). It really takes the rich flavor of this cake to another level!
Super Moist
This chocolate sheet cake is SUPER soft and moist due to a few key ingredients. Firstly, I opted to use a combination of oil and butter (oil for moisture, butter for additional flavor), and they both contribute to how moist the cake is. Some other notable ingredients are soft light brown sugar, eggs and milk.
Chocolate Fudge Frosting
Sticking to the theme of ‘easy’, I wanted to use a rich frosting that didn’t take too long to make. I originally tried a simple chocolate buttercream, but wanted something with more of rich and decadent feel to it.
I then thought of using my original chocolate fudge frosting recipe (which is probably one of my favorite frostings of all time!), but it requires a few hours to set. I then decided to try a more simple version of a chocolate fudge frosting where the frosting is whipped to cool it down quicker. It worked like a charm and was the perfect frosting for this cake. It really takes the cake to another level – a chocolate lovers dream dessert!
How to Make Chocolate Sheet Cake
Chocolate Cake
Preheat oven to 180 °C (350°F) conventional (see note 2 in recipe card below if using a convection oven with a fan) and lightly grease a 9×13 inch cake pan (I use my homemade cake release). Line the bottom long ways with parchment paper (this will make it easier to take the cake out when it’s done).

Sift together flour, cocoa powder, baking powder, baking soda and salt. Using a whisk or fork, mix until well combined and set aside for now.
In a large bowl add in brown sugar, white sugar, milk, melted butter, unflavored vegetable oil, eggs and vanilla. Using a whisk, stir until well combined.

Add in the flour mixture from earlier to the wet ingredients and mix with a whisk until just combined. Do not overmix.

Add in hot coffee (make sure to boil the water used to make the coffee close to when it needs to go into the batter) and mix with a whisk until well combined. The mixture should be smooth, but avoid overmixing.

Pour the batter into the prepared cake pan from earlier. Drop the cake pan lightly on the counter to remove any large air bubbles and bake for 27 minutes, or until a toothpick inserted into the centre comes out clean or with a few moist crumbs on it.

Allow the cake to cool in the cake pan for 20 minutes, before carefully turning it out onto a wire rack to completely cool. Once cooled, carefully invert onto a serving plate (see video for demonstration if unsure of the best way to do this) and frost with chocolate fudge frosting (recipe below).

Chocolate Fudge Frosting
Place saucepan over a low-medium heat and add in butter. Allow it to melt, keeping a close eye on it to ensure it doesn’t burn. Once it starts to gently bubble, add in cocoa powder and mix with a spatula until smooth. Once smooth, mix for a further 10 seconds (make sure the heat isn’t too high – make it lower if it feels like the mixture is catching too quickly on the bottom of the pan) and then transfer the mixture to a large heatproof bowl.

To the mixture add in powdered sugar, milk (make sure it’s room temperature NOT cold), vanilla and salt. Using a hand or stand mixer, mix on a low speed until everything is combined and then turn up the speed to a medium-high and whip for anywhere between 2-5 minutes, until the frosting thickens up and is a smooth spreadable consistency (but still a little loose – see note 3). Mixing time will vary depending on how cold the temperature is 🙂


Spread over the cake using an offset spatula or the back of a tablespoon. Enjoy!

How to Store Chocolate Sheet Cake
This chocolate sheet cake can be left at room temperature in an airtight container for two days, after which it’s best to store in the refrigerator for up to a week.

Moist Chocolate Sheet Cake
IMPORTANT: For accuracy, I would recommend using the gram measurements provided, as those are the exact quantities I use. Cup measurements are given as estimates (based on US cup measurements) to make it easier for those who do not have a scale.
Ingredients
Chocolate Cake
- 1¾ cups (210 g) all purpose flour
- ¾ cup (75 g) cocoa powder - Dutch processed preferred (see note 1)
- 2 tsp baking powder
- 1 tsp baking soda
- 1 tsp salt - only use 1/2 tsp if using salted butter in this recipe
- 1 cup (200 g) soft light brown sugar
- 1 cup (200 g) white granulated sugar
- ¾ cup (180 g) milk - room temperature, whole milk
- ¼ cup (56 g) unsalted butter - melted
- ½ cup (105 g) unflavored vegetable oil - I use canola oil
- 2 large eggs - room temperature
- 2½ tsps vanilla extract/essence
- ¾ cup (180 g) strong hot coffee - I use 1 tbsp instant coffee powder in 180g (¾ cup) hot water, but you can use espresso as well.
Chocolate Fudge Frosting
- ½ cup (113 g) unsalted butter
- ⅔ cup (66 g) cocoa powder - Dutch processed preferred (see note 1)
- 2½ cups (315 g) powdered sugar - also known as icing/confectioners sugar
- ⅓ cup (80 g) milk - room temperature, whole milk
- 1½ tsps vanilla
- ⅛ tsp salt - omit if using salted butter, though I do recommend using unsalted 🙂
Instructions
Chocolate Cake
- Preheat oven to 180 °C (350°F) conventional (see note 2 if using a convection oven with a fan) and lightly grease a 9x13 inch cake pan (I use my homemade cake release). Line the bottom long ways with parchment paper (this will make it easier to take the cake out when it's done).
- Sift together flour, cocoa powder, baking powder, baking soda and salt. Using a whisk or fork, mix until well combined and set aside for now.
- In a large bowl add in brown sugar, white sugar, milk, melted butter, unflavored vegetable oil, eggs and vanilla. Using a whisk, mix until well combined.
- Add in presifted dry ingredients from earlier to the wet ingredients and mix with a whisk until just combined. Do not overmix.
- Add in hot coffee and mix with a whisk until well combined. The mixture should be smooth, but avoid overmixing.
- Pour the batter into the prepared cake pan from earlier. Drop the cake pan lightly on the counter to remove any large air bubbles and bake for 27 minutes, or until a toothpick inserted into the centre comes out clean or with a few moist crumbs on it.
- Allow the cake to cool in the cake pan for 20 minutes, before carefully turning it out onto a wire rack to completely cool. Once cooled, carefully invert onto a serving plate (see video for demonstration if unsure of the best way to do this) and frost with chocolate fudge frosting (recipe below).
Chocolate Fudge Frosting
- Place saucepan over a low-medium heat and add in butter. Allow it to melt, keeping a close eye on it to ensure it doesn't burn.
- Once it starts to gently bubble, add in cocoa powder and mix with a spatula until smooth. Once smooth, mix for a further 10 seconds (make sure the heat isn't too high otherwise the cocoa will burn - make it lower if it feels like the mixture is catching too quickly on the bottom of the pan) and then transfer the mixture to a large heatproof bowl.
- To the mixture add in powdered sugar, milk (make sure it's room temperature NOT cold), vanilla and salt. Using a hand or stand mixer, mix on a low speed until everything is combined and then turn up the speed to a medium-high and whip for anywhere between 2-5 minutes, until the frosting thickens up and is a smooth spreadable consistency (but still a little loose - see note 3). Mixing time will vary depending on how cold the temperature is 🙂
- Spread over the cake using an offset spatula or the back of a tablespoon. Enjoy!
Video
Notes
Nutrition
Nutritional information are estimates only as they are automatically calculated by a third party application. Actual values may differ based on brands and types of products used.
114 Comments
Hello Maryam! Thank you for this recipe! I made it twice and it’s delicious, suuuuuuuper moist and soft. However, the two times the cakes sink in the middle by the end of the baking time 🙁 I am following everything except for the baking tray, I am using 6 inches rounded cake tins (4 layers in total with the recipe). Could this be the reason for sinking? Do you know if there are other reasons why it keeps sinking?
Thank you so much!!!!
Hi Melissa! 🙂 So sorry to hear you’re having trouble with the cakes sinking in the middle – that can be frustrating! Yes the cake tins could be the issue – if they’re overfilled then they may not rise well. Also, do you notice they take a bit longer to cook? If so, you may be checking them a bit too early which is causing them to sink. I would recommend only checking the cakes when they’re almost done 🙂
Check out this blog post for some more troubleshooting tips: https://cakesbymk.com/recipe/why-did-my-cake-sink-in-the-middle/
Hope that helps for next time Melissa 🙂
10/10. Superb recipe that I have made several times. The cake is soft, rich, and moist, and I have used the frosting for several other cake recipes. It has quickly become one of my favorite cake recipes.
Aww yay! So glad you’re loving the recipe Rose 😀
Really appreciate the wonderful feedback 🙂
Hi do you know what the measurements would be for making a half sheet pan of this chocolate cake? Or would I just double it?
Hi Tammy! Yes for a half sheet simply double the recipe 🙂
Enjoy!
Can I use 2 cups white sugar instead of 1 cup brown and 1 cup white
Hi Kulthum! 🙂 Yes you can do that, it’ll just change the texture of the cake a little but it’ll still be great 🙂
Enjoy!
You are our queen.
Sounds yummy!! Can’t wait to try it!! Thanks for sharing! Bless you!
Thanks Diane! 🙂 Hope you enjoy the recipe 😀
I made this for a potluck last weekend. It was amazing. I am not usually a big fan of dutch cocoa as it hasn’t had the very chocolate flavor of natural cocoa to me. It is probably because I am just used to the natural cocoa. I followed your suggestion and used dutch but have to admit I was skeptical. It turned out amazing and I was seeing people going back for seconds and one of them is not a fan of sweets. I did find it a bit crumbly but still very moist and flavorful I especially loved the fudge frosting. Thank you for sharing this and I will be making it again.
So so happy to hear everyone loved the recipe Maggie! 😀
Really appreciate the wonderful feedback 🙂
Hope you publish a book soon. With all your recipes as is on you website. It’s going to be a bestseller that’s for sure.
Aww this means so much to me Eileen! Thank you so much for all your love and support, I truly appreciate it 🙂
I can’t wait to try this recipe! Chocolate sheet cake is my favorite! Thanks for sharing this recipe.
Hope you love the recipe Judy! 😀
I would love to make this cake for my daughter but she’s allergic to dairy. Do you have any recommendations to make it dairy free?
Hi Toni! 🙂 Hmm to be honest I haven’t baked much with dairy substitutes so I’m not too sure sorry! I have had other readers who are vegan substitute the milk in some of my recipes with almond milk and butter with a plant based butter and that seems to have worked well. So sorry I couldn’t be of more help!