Chocolate Sheet Cake is the recipe that Lucia makes every time she needs to bring a genuinely spectacular dessert to a large gathering and wants something that is completely effortless to transport, requires no layering or assembly, serves twenty people from a single pan, and impresses every single person at the table as deeply as any multi-layer celebration cake ever could. She discovered early in her sheet cake adventures that the combination of Dutch cocoa powder, buttermilk, sour cream, and hot coffee produces something extraordinary in a large pan. And then she found the secret that changed the frosting entirely.
Hot fudge sauce stirred into the chocolate buttercream produces a depth and a glossiness and a richly fudgy quality that plain cocoa and sugar buttercream simply cannot approach.
Chocolate Sheet Cake is the crowd-feeding dessert that delivers a truly extraordinary eating experience to fifteen to twenty people from a single 9 by 13-inch pan with minimal preparation, no assembly stress, and a frosting that is genuinely the most decadent and richly flavored chocolate buttercream you have ever spread onto a cake. Dutch-process cocoa, buttermilk, sour cream, and hot coffee in the batter for the most deeply moist and fudgy sheet cake, and hot fudge sauce stirred into the chocolate buttercream for a frosting that is completely spectacular. Come follow us on Pinterest where we share beautiful chocolate cake recipes and easy crowd desserts from our kitchen every single week.
Table of Contents
Why You Will Love This Chocolate Sheet Cake Recipe
This Chocolate Sheet Cake recipe is the large-format dessert that answers every hosting challenge simultaneously. One pan, no layers, no assembly, no stress, and a finished product that looks genuinely impressive and tastes completely extraordinary. The sour cream in the batter is the first secret ingredient that makes this sheet cake so exceptional. Sour cream adds fat, acidity, and moisture simultaneously, and its slight tang tenderizes the crumb through acid reduction of gluten while its richness keeps the cake soft for several days after baking.
The hot fudge sauce added to the buttercream is the second and most delightfully surprising element of this recipe. Commercial hot fudge sauce stirred into a conventional chocolate buttercream transforms a good frosting into a genuinely spectacular one with a deeper chocolate flavor, a more complex sweetness, and a velvety and slightly glossy texture that is completely distinct from a plain buttercream. Our Cheesy Pepperoni Stromboli makes a wonderfully satisfying and crowd-pleasing companion savory bake for a complete and celebratory gathering spread before this spectacular chocolate dessert.
Ingredients Needed for This Chocolate Sheet Cake Recipe
For the Cake:
- 3 cups All-Purpose Flour (360g)
- 2⅔ cups Granulated Sugar (530g)
- ½ cup Dutch-Process Cocoa Powder (50g)
- 2 tsp Baking Soda
- 1½ tsp Baking Powder
- ¾ tsp Salt
- 1 cup Buttermilk, room temperature
- ½ cup Full-Fat Sour Cream, room temperature
- 3 large Eggs, room temperature
- ¾ cup Vegetable Oil
- 1 tbsp Pure Vanilla Extract
- 1½ cups Hot Strong Coffee or Boiling Water
For the Chocolate Fudge Buttercream:
- 1½ cups Unsalted Butter, room temperature (340g)
- ¼ cup Dutch-Process Cocoa Powder (25g)
- ¾ tsp Salt
- 1 lb Powdered Sugar (450g)
- 1 to 3 tbsp Whole Milk or Heavy Cream
- ⅓ cup Hot Fudge Sauce or Chocolate Ganache (100g)
How to Make This Chocolate Sheet Cake Recipe
Preheat the oven to 350°F. Lightly grease a 9 by 13-inch cake pan with baking spray. If you plan to remove the cake from the pan before serving, line it with a parchment paper sling with extra paper hanging over the two long sides for easy lifting.
In a large bowl, sift together the flour, granulated sugar, Dutch cocoa powder, baking soda, baking powder, and salt, then whisk to combine fully. In a separate medium bowl, whisk together the room-temperature sour cream, buttermilk, eggs, vegetable oil, and vanilla extract until combined. Slowly whisk the hot coffee or boiling water into the wet ingredient bowl.
Adding the hot liquid last and into the wet ingredients rather than directly into the batter is the technique that more rapidly hydrates the flour when the two mixtures are combined, producing a more moist and slightly fudgy finished texture. Slowly pour the wet ingredient mixture into the dry ingredients and whisk until completely smooth with no flour streaks remaining. Pour the batter into the prepared pan.
Bake for 45 to 50 minutes until the center of the cake feels springy when gently pressed and the edges are beginning to pull away from the sides of the pan. Do not test this cake with a toothpick before it is fully set as poking an under-baked chocolate sheet cake can cause it to sink and collapse in the center. Allow the cake to cool completely in the pan before frosting, cara mia.
For the frosting, beat the room-temperature butter in a stand mixer or large bowl on medium speed for about 2 minutes until smooth and creamy. Add the cocoa powder and salt and mix on low until fully combined. With the mixer on low, gradually add the powdered sugar in half-cup increments, stopping to scrape down the bowl occasionally. Once all the powdered sugar is incorporated, add the hot fudge sauce or ganache and mix on medium-low until fully combined. Beat in enough milk or cream to make the frosting smooth, fluffy, and easily spreadable without being runny.
Spread the buttercream generously over the completely cooled sheet cake using an offset spatula in swooping strokes for the most beautiful and rustic presentation.
How to Serve This Chocolate Sheet Cake Recipe
This cake can be served directly from the pan at the table which is the most practical and informal option for large gatherings. Alternatively, lift the cooled unfrosted cake from the pan using the parchment sling, discard the parchment, and frost on a serving board or large platter for a more elegant presentation.
Cut into thirds lengthwise and fifths crosswise for 15 generous servings, or into fourths and fifths for 20 portions. This cake can feed up to 30 people with thinner slices for a very large crowd. Our Sausage and Egg Casserole makes a wonderfully hearty and crowd-feeding companion for a complete and joyful large-gathering menu alongside this spectacular chocolate dessert.
How to Store This Chocolate Sheet Cake Recipe
Store the frosted sheet cake in an airtight container at room temperature for up to 5 days. Because the batter uses vegetable oil as the primary fat, the cake stays soft and moist at room temperature for the full storage period without needing refrigeration. For longer storage, freeze the unfrosted cake wrapped in plastic wrap and aluminum foil for up to 1 month.
The frosting can be made 2 days ahead and stored in an airtight container in the refrigerator. Bring to room temperature and beat again briefly until light and fluffy before applying to the cake.
Tips to Make This Chocolate Sheet Cake Recipe
Use a lighter-colored metal pan for the best results. Darker metal pans conduct heat more aggressively and can produce hardened or burnt edges on the cake before the center has cooked through. Glass and ceramic pans can also be used but they insulate heat and require a few extra minutes of baking time and may produce a slightly different exterior texture.
Test the doneness of the sheet cake by pressing the center gently with your fingertip rather than inserting a toothpick. A quick firm press of the center is fast enough not to burn and if the cake springs back immediately it is done. A toothpick inserted into an under-baked chocolate sheet cake can cause the center to sink and collapse before it has built enough structure to support itself.
Helpful Notes for This Chocolate Sheet Cake Recipe
Dutch-process cocoa powder is specifically recommended over natural cocoa powder for this sheet cake recipe. Dutch-process cocoa produces a deeper, darker, and more intensely chocolate-flavored result than natural cocoa in a recipe of this scale. The large quantity of batter benefits most from the richer flavor output of Dutch-process. Because there is no baking-soda leavening reaction dependent on cocoa acidity in this specific formulation, either cocoa type will produce a properly risen cake but the flavor difference is meaningful and Dutch-process is significantly better here.
The question of whether to use hot coffee or boiling water is simply a matter of preference. Hot coffee produces a cake with a noticeably deeper and more complex chocolate flavor. Boiling water produces a more purely chocolate-tasting cake without any coffee dimension. Both versions are deeply moist and completely delicious. Decaf coffee works identically to regular coffee in this recipe.
Variation of This Chocolate Sheet Cake Recipe
Maria made a version adding a cup of chocolate chips folded through the batter just before pouring into the pan for a chocolate chip sheet cake that had warm melty chocolate pockets throughout every slice and was completely extraordinary at a large family gathering. Teresa tried topping the frosted cake with a generous handful of toasted chopped pecans pressed into the frosting for a chocolate pecan sheet cake that tasted like a completely indulgent and deeply nutty celebration.
For a birthday party version, add bright sprinkles over the frosted cake immediately after spreading so they adhere before the frosting sets for the most festive and completely joyful visual that delights children and adults alike. Our Dole Whip Cupcakes with Pineapple Filling make a beautifully tropical and individually portioned companion for a complete and vibrant party dessert table alongside this spectacular chocolate sheet cake.
FAQs About This Chocolate Sheet Cake Recipe
Can I use melted butter instead of vegetable oil in the batter?
Yes. Melted butter produces a richer and more deeply flavored sheet cake. However, vegetable oil produces a more durably moist cake because oil remains liquid at room temperature and in the refrigerator rather than resolidifying as butter does when cooled. An oil-based cake stays soft for days longer than a butter-based cake of the same recipe. The choice depends on whether flavor depth or keeping quality is the higher priority.
Can I make this into layer cakes instead?
Yes. The same batter quantity makes three 8-inch round cake layers baked for 30 to 35 minutes at the same temperature, or three 9-inch layers baked for 25 to 30 minutes. The same frosting quantity is sufficient for a three-layer round cake.
How far in advance can I make this cake?
The unfrosted sheet cake stays moist and delicious for up to 5 days at room temperature tightly covered. The frosting can be made 2 days ahead and refrigerated. For the most practical make-ahead approach, bake the cake 1 to 2 days before the event, make the frosting the morning of, and frost a few hours before serving.
Conclusion
This Chocolate Sheet Cake is the crowd dessert that makes hosting a large gathering genuinely joyful rather than stressful, feeds every person at the table a generous and deeply satisfying slice from a single pan, and delivers a chocolate experience that is so extraordinarily moist and so richly and fudgily frosted that it becomes the recipe everyone at the gathering asks for before they leave. Make it, share it, and come back to tell us all about it. With all our love, Maria, Lucia, and Teresa.
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Chocolate Sheet Cake The Most Moist and Easy Crowd Dessert You Will Ever Bake
- Total Time: 2 hours including cooling
- Yield: 15 to 20 servings 1x
- Diet: Vegetarian
Description
The most moist and easy Chocolate Sheet Cake made with Dutch cocoa powder buttermilk sour cream and hot coffee for the most deeply fudgy and tender crumb frosted with a decadent chocolate buttercream made with hot fudge sauce for an extraordinary velvety and richly chocolatey frosting. Serves 15 to 20 from one 9×13 inch pan.
Ingredients
3 cups All-Purpose Flour
2 2/3 cups Granulated Sugar
1/2 cup Dutch-Process Cocoa Powder
2 tsp Baking Soda
1 1/2 tsp Baking Powder
3/4 tsp Salt
1 cup Buttermilk room temperature
1/2 cup Full-Fat Sour Cream room temperature
3 large Eggs room temperature
3/4 cup Vegetable Oil
1 tbsp Pure Vanilla Extract
1 1/2 cups Hot Strong Coffee or Boiling Water
1 1/2 cups Unsalted Butter room temperature for frosting
1/4 cup Dutch-Process Cocoa Powder for frosting
3/4 tsp Salt for frosting
1 lb Powdered Sugar
1 to 3 tbsp Whole Milk or Heavy Cream
1/3 cup Hot Fudge Sauce or Chocolate Ganache
Instructions
1. Preheat oven to 350°F. Grease a 9×13-inch cake pan. Line with parchment sling if removing from pan.
2. Sift and whisk flour, sugar, cocoa, baking soda, baking powder, and salt in a large bowl.
3. Whisk sour cream, buttermilk, eggs, oil, and vanilla in a medium bowl.
4. Slowly whisk hot coffee into the wet ingredients.
5. Pour wet into dry. Whisk until completely smooth with no flour streaks.
6. Pour into prepared pan.
7. Bake 45 to 50 minutes until center feels springy when pressed and edges pull from pan.
8. Cool completely in pan before frosting.
9. Beat butter 2 minutes until creamy.
10. Add cocoa and salt on low until combined.
11. Add powdered sugar gradually on low stopping to scrape bowl.
12. Add hot fudge and mix on medium-low until combined.
13. Beat in milk or cream until smooth fluffy and spreadable.
14. Spread frosting generously over cooled cake using offset spatula.
- Prep Time: 10 minutes
- Cook Time: 50 minutes
- Category: Dessert, Cake
- Method: Baking
- Cuisine: American
Nutrition
- Serving Size: 1 slice
- Calories: 676
- Sugar: 69g
- Sodium: 489mg
- Fat: 33g
- Saturated Fat: 15g
- Unsaturated Fat: 15g
- Trans Fat: 0g
- Carbohydrates: 93g
- Fiber: 2g
- Protein: 6g
- Cholesterol: 87mg
Keywords: chocolate sheet cake, moist chocolate sheet cake recipe, easy chocolate sheet cake for crowd, hot fudge chocolate buttercream cake
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