Richest Chocolate Sheet Cake is everything you could dream of from a chocolate cake... and more. It's thick, moist, fluffy, made in two bowls, calls for simple ingredients, and is SO fudgy. If this was the only cake I could bake and eat for the rest of my life, I'd be okay.... more than okay.

Ditch the Cake Mix
I know what you might be thinking. If I'm going to make a sheet cake, why wouldn't I just grab a cake mix from the grocery store. I get it... a $1.50 cake mix is tempting. It will never tempt you again after trying THIS sheet cake recipe.
I knew this cake was going to be good just 7 minutes after I popped it in the oven. The chocolate smell that filled my house was... overwhelming... to say the least. This cake is moist beyond belief, and it's so dang chocolatey. It truly hits you with flavor. Until this cake, I hadn't had a RICH chocolate cake. This cake hits you with DEEP, thick chocolate!

Sheet Cake Process
This richest chocolate sheet cake recipe is one that you'll have ready before your oven is finished preheating. Those are my favorite recipes, as they truly rival the ease and quickness of a store-bought cake or a box mix. The effort to make this cake? Minimal. The time needed to make this cake? Very little. Below is LITERALLY all this cake is-
- Preheat oven and prepare pan
- Whisk the dry ingredients in one bowl
- Whisk the wet ingredients in another bowl
- Mix wet and dry ingredients together
- Pour batter into pan
- Bake
- Cool
- Frost

Room Temperature Ingredients
When I tell you that room-temperature ingredients make all the difference in the world, please believe me. 5 years ago, I would've never believed me, so I have been there, but your treats WILL NOT come out as they are intended to if you don't follow the recipe.
In this recipe, we have lots of ingredients that need to be at room temperature. If you forget to leave them out 1-2 hours ahead of time, you should:
- Milk: Microwave your milk for 15 seconds.
- Sour Cream: Microwave your sour cream for 10 seconds.
- Eggs: Place your eggs in a bowl of warm water for 10 minutes before baking.

FAQ
To my knowledge, sheet cake is normal cake batter baked in a rectangular, slightly more shallow pan. Sheet cakes are attractive due to how much easier they are to bake, decorate, serve, and store!
You can absolutely make this in an 8x8 pan. The recipe below is for a standard 9x13 sheet pan, but if you'd like to make an 8x8, simply halve the recipe! The baking time will be very close to the bake time listed in the recipe!
You CAN make this into a layer cake! I would recommend a three-layered 6 inch cake or 2-layered 8 inch cake! You will need to adjust the baking time, though the cake will still have the same baking cues as listed in the recipe below.

Variations
Sour Cream: Sour cream can be substituted with Greek yogurt.
Buttermilk: Buttermilk should not be substituted with any other type of milk. However, you can make homemade buttermilk by adding 1 tablespoon of white distilled vinegar or lemon juice to a liquid measuring cup and adding enough regular milk to fill up to 1 cup. Stir the mixture and let it sit for 5-10 minutes before using!
Oil: If you do not have vegetable oil, you can substitute it with any other unflavored oil.
Icing: You can do WHATEVER you'd like for the frosting! Use the recipe below, use your grandma's famous recipe, use store-bought... whatever you'd like to do!
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Richest Chocolate Sheet Cake
- Prep Time: 10 minutes
- Cook Time: 35 minutes
- Total Time: 45 minutes
- Yield: 9x13 cake 1x
- Category: Cake, Chocolate Cake, Vanilla Buttercream
- Cuisine: American
Description
Richest Chocolate Sheet Cake is everything you could dream of from a chocolate cake... and more. It's thick, moist, fluffy, made in two bowls, calls for simple ingredients, and is SO fudgy. It's topped with a classic American Buttercream and is simply the most delicious treat.
Ingredients
For the Cake
- 1 ¾ cup (245g) all purpose flour
- 1 ¾ cup (363g) granulated sugar
- ⅔ cup (56g) cocoa powder
- 2 teaspoons (10g) baking soda
- ½ teaspoon (2g) baking powder
- 1 teaspoon (5g) salt
- 2 large eggs (100g), room temperature
- ½ cup (130g) sour cream, room temperature
- 1 cup (225g) buttermilk, room temperature
- ½ cup (100g) vegetable oil
- 1 teaspoon (4g) vanilla
- ¾ cup (160g) hot water
For the Frosting
- 1 cup unsalted butter (can be cold if using a stand mixer)
- ½ cup vegetable shortening
- 1 teaspoon vanilla extract
- 4 cups powered sugar
- 2 tablespoons heavy whipping cream
Instructions
For the Cake
- Preheat your oven to 350 degrees Fahrenheit. Line a 9×13 pan with parchment paper, spraying the paper and sides of the pan with cooking spray to ensure easy removal of the cake!
- In a large bowl, whisk flour, sugar, cocoa powder, baking soda, baking powder, and salt until fully mixed.
- In a medium-sized bowl, whisk eggs, sour cream, buttermilk, vegetable oil, and vanilla until ingredients are fully combined.
- Add wet ingredients to dry ingredients, whisking for about 10 seconds before adding half of the hot water to the bowl. Once the water is beginning to incorporate, add the other half of the water. Mix until all ingredients are combined, making sure to scrape down the sides of the bowl and ensuring that the mixture at the bottom of the bowl reaches the same consistency as the rest of your batter.
- Pour your batter into your prepared pan. Bake for 30-35 minutes or until a toothpick inserted into the center comes out with moist, formed crumbs.
- Let cool for at least 30 minutes before frosting. Frosting will melt if the cake is still warm.
For the Frosting
- In a large bowl or in the bowl of a stand mixer fitted with a paddle attachment, cream the butter and vegetable shortening together on medium/ high speed. Mixture should be smooth and fully combined. Add vanilla.
- Slowly add powdered sugar to the butter mixture over low speed. Frosting will become crumbly but will smoothen out as you continue mixing.
- Pour heavy whipping cream into the frosting. Mix on high speed for at least 3 minutes. Frosting will become light and fluffy.
- Spread on cooled sheet cake. Store covered at room temperature for up to 4 days.
Keywords: Chocolate Sheet Cake, Chocolate Cake, American Buttercream
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