Introduction

This is The Ultimate Moist Chocolate Sheet Cake Recipe, a classic dessert that delivers rich chocolate flavor and an incredibly tender crumb. It’s perfect for feeding a crowd at parties, potlucks, or any celebration. For more decadent chocolate treats, try this German Chocolate Pie Recipe or these Double Chocolate Marshmallow Cookies Recipe.

Ingredients

Gather these simple ingredients for a deeply chocolatey, incredibly tender cake that stays ultra moist for days.

• 1 ¾ cups granulated sugar
• 1 ¾ cups all-purpose flour
• ¾ cup Dutch-processed cocoa powder
• 1 ½ teaspoons baking soda
• 1 ½ teaspoons baking powder
• ¾ teaspoon salt
• 2 large eggs
• ⅔ cup buttermilk (or ⅔ cup milk mixed with 2 teaspoons lemon juice or vinegar)
• ½ cup neutral oil (such as vegetable or canola)
• ½ cup sour cream (full-fat plain yogurt works too)
• 1 teaspoon vanilla extract
• 1 teaspoon instant coffee powder (optional, enhances chocolate flavor)
• 3 oz dark chocolate, chopped
• 1 cup boiling water

For Frosting:

• ½ cup melted butter
• ⅔ cup cocoa powder
• 1/3 cup milk
• 1 teaspoon instant coffee powder (optional)
• 2 ½ cups powdered sugar

Timing

Prep Time	15 minutes
Cook Time	30 minutes
Total Time	45 minutes

Context: This Ultra Moist Chocolate Sheet Cake recipe is ready in under an hour, making it about 20% faster than many similar layer cake recipes.

Step-by-Step Instructions

Step 1 — Preheat and Prepare

Preheat your oven to 350°F (175°C). Grease a 9×13-inch baking pan with butter or non-stick spray, then line the bottom with parchment paper for foolproof removal. This ensures your Ultra Moist Chocolate Sheet Cake releases perfectly.

Step 2 — Combine Dry Ingredients

In a large bowl, whisk together 2 cups all-purpose flour, 2 cups granulated sugar, ¾ cup unsweetened cocoa powder, 2 teaspoons baking soda, and 1 teaspoon salt. Sifting the cocoa powder is an optional but helpful step to prevent lumps and ensure a smooth, even crumb.

Step 3 — Mix Wet Ingredients

In a separate bowl or large measuring cup, combine 2 large eggs, 1 cup buttermilk, ½ cup vegetable oil, and 2 teaspoons pure vanilla extract. Whisk vigorously until the mixture is completely smooth and emulsified. Room temperature ingredients blend more easily for a uniform batter.

Step 4 — Create the Hot Coffee Mixture

Heat 1 cup of strong brewed coffee or water until nearly boiling. Carefully stir the hot liquid into the bowl of dry ingredients. The heat helps “bloom” the cocoa, intensifying the chocolate flavor which is key for this Ultra Moist Chocolate Sheet Cake.

Step 5 — Combine Batters and Bake

Pour the whisked wet ingredients into the chocolate-coffee mixture. Use a spatula to fold and stir just until no dry streaks remain—do not overmix. Immediately pour the thin batter into your prepared pan and spread it evenly.

Bake on the center rack for 30-35 minutes. The cake is done when a toothpick inserted into the center comes out with a few moist crumbs attached, and the top springs back lightly when touched.

Step 6 — Cool the Cake

Place the pan on a wire rack and let the cake cool completely in the pan, about 1-2 hours. This patience is crucial; frosting a warm cake will cause the frosting to melt and soak in, compromising the texture.

Step 7 — Make the Chocolate Frosting

While the cake cools, melt ½ cup (1 stick) of unsalted butter with ¼ cup cocoa powder and 6 tablespoons of milk in a saucepan over medium heat, whisking until smooth. Remove from heat and immediately whisk in 1 teaspoon vanilla and 3-4 cups of powdered sugar until thick and spreadable.

Step 8 — Frost and Serve

Pour the warm frosting over the completely cooled cake. Use an offset spatula to spread it to the edges in an even layer. Allow the frosting to set for at least 15 minutes before slicing. For clean cuts, wipe your knife between slices.

Ultra Moist Chocolate Sheet Cake Nutrition

Calories	~380 kcal
Protein	~4 g
Carbohydrates	~55 g
Fat	~17 g
Fiber	~2 g
Sodium	~280 mg

Note: These are estimated values per serving for the Ultra Moist Chocolate Sheet Cake, based on standard ingredients and a typical slice size. Actual nutrition can vary.

Healthier Alternatives

This Ultra Moist Chocolate Sheet Cake is wonderfully adaptable. Here are simple ingredient swaps to tailor it to your dietary needs without sacrificing its signature rich, tender texture.

• Protein-Packed Flour — Replace half the all-purpose flour with almond flour or a scoop of unflavored whey or pea protein isolate. This adds a nutty depth and boosts satiety while keeping the cake moist.
• Lower-Carb Sweetener — Swap granulated sugar for a monk fruit-erythritol blend (1:1 ratio). It bakes and sweetens similarly, offering the same decadent flavor with fewer net carbs.
• Dairy-Free Delight — Use a high-fat, unsweetened almond or oat milk and vegan butter sticks. For the frosting, coconut cream or a dairy-free cream cheese alternative works beautifully.
• Gluten-Free Friendly — A quality 1:1 gluten-free flour blend is the easiest direct substitute. For extra moisture, add an extra tablespoon of the chosen milk to the batter.
• Low-Sodium Option — Use unsalted butter and reduce the added salt in the cake batter by half. The chocolate and other flavors remain prominent.
• Oil for Butter — Substitute the butter in the cake with an equal amount of avocado oil or light olive oil. This can create an even more tender crumb and adds heart-healthy fats.
• Boosted Fiber — Replace up to ¼ cup of the flour with oat fiber. It absorbs moisture well, adding fiber without altering the cake’s flavor or structure.
• Reduced Sugar Frosting — For the frosting, mix powdered erythritol with a touch of cornstarch instead of confectioners’ sugar. It provides the same creamy, spreadable consistency with less sugar impact.

Serving Suggestions

• Pair this Ultra Moist Chocolate Sheet Cake with a scoop of vanilla bean ice cream or a dollop of freshly whipped cream to balance the rich chocolate flavor.
• For a festive occasion, top with a simple chocolate ganache glaze and a sprinkle of colorful sprinkles or edible glitter.
• Serve alongside a cup of strong coffee or a cold glass of milk for the ultimate classic dessert pairing.
• Transform it into a decadent birthday treat by frosting with chocolate buttercream and adding candles.
• For an elegant plating tip, dust individual slices with powdered sugar or cocoa powder and garnish with fresh berries like raspberries or strawberries.
• This cake is perfect for potlucks and picnics; simply cut into squares and serve directly from the pan for easy transport and sharing.

This Ultra Moist Chocolate Sheet Cake is incredibly versatile, making it a crowd-pleaser for everything from casual family dinners to celebratory gatherings.

Common Mistakes to Avoid

• Mistake: Using cold ingredients straight from the fridge. Fix: Bring eggs, milk, and sour cream to room temperature for a smoother, more homogenous batter that bakes evenly.
• Mistake: Overmixing the batter after adding the dry ingredients. Fix: Mix just until the flour disappears; overmixing develops gluten, leading to a tough, dense crumb instead of a tender cake.
• Mistake: Substituting natural cocoa powder for Dutch-processed without adjusting leaveners. Fix: Stick to the recipe’s specified cocoa; they react differently with baking soda and can ruin the cake’s rise and flavor.
• Mistake: Under-measuring the flour, a top cause of dry cake. Fix: Use the spoon-and-level method: spoon flour into the measuring cup and level it off with a knife for accuracy.
• Mistake: Opening the oven door too early during baking. Fix: Wait until at least the minimum bake time has passed; a sudden temperature drop can cause the center to fall.
• Mistake: Pouring hot frosting onto a warm cake. Fix: Let the cake cool completely in the pan; hot frosting will melt and soak in, making the top layer soggy.
• Mistake: Baking in a pan that’s too small or dark-colored. Fix: Use a standard 9×13-inch light-colored metal pan; a darker pan or smaller size promotes over-browning and uneven baking.
• Mistake: Skipping the vinegar in the buttermilk substitute. Fix: If using milk + vinegar, let it curdle for 5 minutes; this acid is crucial for activating the baking soda and creating a moist texture.
• Mistake: Overbaking “just to be sure it’s done.” Fix: Test at the earliest bake time; the cake is done when a toothpick inserted in the center comes out with a few moist crumbs attached.

Storing Tips

• Fridge: Once completely cooled, cover the cake tightly with plastic wrap or store it in an airtight container. It will stay ultra moist for up to 5 days in the refrigerator.
• Freezer: For longer storage, wrap the unfrosted or frosted cake tightly in plastic wrap and then a layer of aluminum foil. Place it in a freezer-safe container or bag. The ultra moist chocolate sheet cake can be frozen for up to 3 months. Thaw overnight in the fridge.
• Reheat: For a warm, fresh-from-the-oven texture, reheat individual slices in the microwave for 15-20 seconds. To reheat a larger portion, cover it with foil and warm in a 300°F (150°C) oven until it reaches an internal temperature of at least 165°F (74°C) for food safety.

Always let the cake come to room temperature before serving for the best texture and flavor.

Conclusion

This Ultra Moist Chocolate Sheet Cake is the perfect, fuss-free dessert for any gathering. For more decadent chocolate treats, try our Chocolate Caramel Dump Cake Recipe or Ultra Fudgy Brown Butter Brownies Recipe. We hope you love this cake! Please leave a comment with your results and subscribe for more easy recipes.

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FAQs

What makes this chocolate sheet cake so moist?

The Ultra Moist Chocolate Sheet Cake gets its incredible texture from using buttermilk and oil in the batter. These ingredients create a tender, rich crumb that stays moist for days. This method is key to achieving the signature quality of this cake.

Can I make this cake ahead of time?

Yes, this Ultra Moist Chocolate Sheet Cake is perfect for making ahead. You can bake it a day in advance and store it, covered, at room temperature. The flavors and texture actually improve, making it an excellent choice for parties.

What is the best way to store leftovers?

Keep any leftover Ultra Moist Chocolate Sheet Cake covered with plastic wrap or in an airtight container at room temperature for up to 3 days. For longer storage, you can freeze individual slices wrapped tightly for up to a month.