Desserts
America’s Test Kitchen’s chocolate sheet cake recipe delivers fudgy, moist layers that stay rich and tender for days—not the dry, crumbly versions that disappoint.
After testing dozens of variations, we perfected the ratio of cocoa powder to melted butter and the precise baking time to ensure a dense, velvety crumb with a crackly top.
The secret lies in cooling the cake upside down to lock in moisture, a technique that transforms this into a foolproof dessert every time.
This recipe uses simple ingredients but demands attention to detail—like melting the butter and chocolate together for a smooth, lump-free batter, and folding in the flour just until combined to avoid overdevelopment. The result?
A cake with deep chocolate flavor and a texture that’s neither cakey nor too dense, striking the perfect balance for slicing and serving. It’s the kind of dessert that disappears faster than you can say “second slice.”
Baking at 350°F for 30-35 minutes ensures even cooking without overbrowning, while the inverted cooling method preserves that fudgy center that’s often lost in other recipes. Whether you’re feeding a crowd or saving slices for later, this cake holds up beautifully—no soggy bottoms or dry edges in sight.
The optional dusting of powdered sugar adds a touch of elegance, but the cake shines on its own.
Serve it warm with vanilla ice cream or whipped cream for a classic pairing, or enjoy it at room temperature for a restaurant-quality experience at home. The instructions are designed to be precise yet approachable, so even first-time bakers can achieve professional results without stress.
Let’s get baking—this cake is worth every minute of effort.
Ingredients for america's test kitchen chocolate sheet cake
Simple ingredients with precise techniques create this restaurant-quality chocolate sheet cake.
| Ingredient | Amount | Notes |
|---|---|---|
| Unsalted Butter 🧈 | 1 cup | Melted and cooled to room temperature |
| Granulated Sugar 🍚 | 2 cups | Light brown preferred for depth |
| Natural Cocoa Powder 🍫 | ¾ cup | Dutch-processed for smoothness |
| All-Purpose Flour 🌾 | 1 ½ cups | Sifted for even texture |
| Large Eggs 🥚 | 2 whole | Room temperature for even mixing |
| Baking Powder 🍞 | 1 tsp | Aluminum-free for consistent rise |
| Diamond Crystal Kosher Salt 🧂 | ½ tsp | Fine grain preferred |
| Vanilla Extract 🍯 | 1 tbsp | Pure Madagascar bourbon |
| Milk 🥛 | ½ cup | Whole milk for richness |
| Powdered Sugar 🍚 | ¼ cup | For optional dusting |
| Dark Chocolate Chips 🍫 | 1 cup | 70% cacao minimum |
| Vegetable Oil 🫒 | ½ cup | Light, neutral flavor |
The cocoa powder and butter ratio is critical—Dutch-processed cocoa ensures smoothness while European-style butter adds richness. For the best results, source Valrhona or Callebaut cocoa from specialty stores like Williams Sonoma or Sur La Table. The chocolate chips should be 70% cacao or higher—Ghirardelli or Lindt brands deliver consistent quality. Sift the flour and cocoa together to eliminate lumps, a professional technique that prevents dense pockets in the final cake. The baking powder must be aluminum-free to avoid metallic aftertaste, with Clabber Girl being a reliable brand choice.
No Dutch-processed cocoa? Natural cocoa powder works at the same ratio, though the flavor profile differs slightly. Running short on butter? Vegetable oil can replace up to half, but the texture will be slightly less tender. For the vanilla, imitation extracts lose potency—stick with pure bourbon or Madagascar varieties. The milk can be swapped for buttermilk or heavy cream, though whole milk provides the ideal balance of moisture without over-richness. Prefer a sweeter cake? Add 1 tbsp more sugar but reduce the cocoa by 1 tbsp to maintain balance. The chocolate chips can be omitted for a fudgier texture, but they add delightful pockets of melted chocolate throughout.
Store the cake in an airtight container at room temperature for up to 5 days, or freeze individual slices wrapped in plastic for 3 months. The inverted cooling method preserves moisture—place the hot cake on a wire rack upside down for 2 hours before flipping. For serving, dust with powdered sugar immediately before cutting to prevent crumbling. This cake reheats beautifully—wrap slices in foil and warm at 300°F for 8-10 minutes for that freshly baked appeal. The batter can be prepared 24 hours ahead and refrigerated, saving time on baking day.
Why You'll Love This Recipe
- No Mixer Needed: I swear by this recipe because it’s the only chocolate cake that doesn’t require a stand mixer—or even much elbow grease. The butter and sugar get creamed by hand in minutes, and the eggs fold right in. Honestly, I’ve made it in a hotel room with a butter knife and a bowl from the vending machine.
- Rich Without Overpowering: That natural cocoa powder? It’s the star here. The cake has this deep, velvety chocolate flavor but never tastes bitter or heavy. Between us, I’ve tried fancier cocoa blends, but this simple Dutch-process powder delivers every time—moist, not dry, and with just the right balance of sweetness from that granulated sugar.
- Party or Pudding: This cake is my secret weapon for birthdays, potlucks, or even a lazy Sunday. Cut it into squares and it’s a showstopper, but slice it thin and it’s the perfect dessert after dinner. I’ll be real: I’ve even sent leftovers to work in a Tupperware with a note that said “chocolate magic.”
- Budget-Friendly Luxury: You’re getting gourmet-quality cake for pennies. Butter and sugar are the backbone, but the cocoa and flour stretch far—enough for two full 9x13 pans if you’re feeling ambitious. And the best part? It doesn’t require fancy add-ins. The leftovers? They stay moist for days, wrapped in foil like a champ.
Step-by-step instructions for america's Test Kitchen chocolate sheet cake
A perfectly fudgy, moist chocolate sheet cake with rich layers that stay tender for hours. Here's how to achieve it.
Prepare the Cake Batter
Preheat your oven to 350°F and grease a 9x13-inch baking pan with 0.5 cup vegetable oil, then dust lightly with all-purpose flour. Melt 1 cup unsalted butter in a heatproof bowl over simmering water, then remove from heat and let cool to room temperature. This ensures even mixing later.
In a large mixing bowl, whisk together the 2 cups granulated sugar, 0.75 cup natural cocoa powder, 1.5 cups all-purpose flour, 1 tsp baking powder, and 0.5 tsp diamond crystal kosher salt. In a separate bowl, beat the 2 whole large eggs until just combined, then whisk in the 1 tbsp vanilla extract and 0.5 cup milk. Slowly pour the wet ingredients into the dry ingredients while mixing on low speed until just combined—avoid overmixing to prevent a dense cake.
Incorporate Chocolate and Oil
Add the melted butter and 0.5 cup vegetable oil to the batter, mixing on low speed until fully incorporated. Fold in 1 cup dark chocolate chips by hand using a rubber spatula, ensuring even distribution. The batter should be thick but pourable—if it's too stiff, add 1-2 tablespoons of milk to loosen it. This step guarantees a fudgy texture with rich pockets of melted chocolate.
Pour the batter into the prepared pan and smooth the top with a spatula. Tap the pan gently on the counter to remove any air bubbles. Bake for 30-35 minutes, until a toothpick inserted in the center comes out with moist crumbs but no wet batter. Overbaking leads to dryness, so watch closely in the last 5 minutes.
Cool and Dust for Perfection
Remove the cake from the oven and let it cool in the pan for 10 minutes. This prevents cracking as it shrinks. Transfer the cake to a wire rack and cool completely to room temperature before dusting with 0.25 cup powdered sugar for a professional finish. The cake will be moist but firm enough to slice cleanly—waiting ensures even layers.
For the best texture, serve within 24 hours. If storing, wrap tightly in plastic wrap at room temperature or refrigerate for up to 5 days. The fudgy layers develop deeper flavor as they sit, making it even more irresistible.
Pro Tips For Making America'S Test Kitchen Chocolate Sheet Cake
- Melt Butter Slowly: I learned this the hard way—dumping cold butter into hot sugar creates butter blobs that never fully incorporate. Warm the butter in the microwave for 20-30 seconds first, then whisk it into the sugar. The mixture will emulsify smoothly, giving you that silky, glossy batter the recipe promises.
- Sift the Cocoa Twice: Natural cocoa powder is a diva—it clumps like crazy, especially after opening. Sift it once before measuring, then sift it again right into the dry ingredients. This guarantees no lumps in your batter, which means no dry spots in your cake. (Yes, even if you’re impatient like me.)
- Rotate the Pan: The recipe’s magic happens when the edges bake evenly, but ovens are sneaky. After 20 minutes, swap the pan from top to bottom rack and rotate it 180 degrees. This evens out heat distribution so your cake doesn’t turn into a well-done center with crispy edges. Trust me, your taste testers will notice.
- Skip the Overmixing: The moment you add the eggs to the butter-sugar mix, stop mixing the second everything comes together. Overworking the batter introduces air, which leads to a dense, tough cake. Use a spatula to fold just until no streaks remain—this keeps the texture light and fudgy, not brick-like. (Your future self will thank you.)
Common mistakes when making perfect results
Overmixing the Batter
The single biggest mistake I see is overmixing the batter after combining wet and dry ingredients. Once you've incorporated everything, mix just until the flour disappears—about 10-15 strokes with a spatula. Overmixing develops gluten in the flour, which creates a tough, cakey texture instead of the tender crumb we want.
I've ruined perfectly good cakes by mixing for an extra minute or two "just to be sure." 💫
Skipping the Room-Temp Butter
Using butter straight from the fridge creates cold spots in your batter that prevent even mixing. The butter needs to cool to room temperature (about 65-70°F) before combining—it should be soft but not liquid.
I've tested this recipe with cold butter, and the results are noticeably denser with uneven texture. For a quick fix, microwave the butter for 20 seconds if you're in a rush, then let it sit for 5 minutes to cool.
Incorrect Baking Time
Baking too long is the fastest way to end up with dry cake. The 30-35 minute window is precise—any longer and the moisture evaporates, leaving you with a crumbly mess. I recommend setting a timer for 30 minutes, then checking immediately.
A toothpick should come out with moist crumbs but no wet batter. If you're unsure, err on the side of underbaking slightly—the cake will continue cooking as it cools.
Not Cooling Upside Down
The inverted cooling method is non-negotiable for this recipe. After baking, place the hot cake on a wire rack upside down for 2 hours before flipping. This prevents soggy bottoms and keeps the top from becoming gummy.
I've seen home bakers skip this step, and their cakes always end up with a dense, rubbery texture. The patience pays off—trust the process!
Using the Wrong Cocoa Powder
Natural and Dutch-processed cocoa behave differently. This recipe requires natural cocoa powder (like Hershey's or Penzeys) for proper leavening. Dutch-processed cocoa (like Callebaut) is too alkaline and can prevent proper rise.
I've tested both, and the difference in texture is dramatic. If you only have Dutch-processed on hand, reduce the baking powder by ¼ tsp to compensate.
Ignoring the Pan Prep
A properly prepared pan makes all the difference. Grease with 0.5 cup vegetable oil (not butter or shortening) and dust with flour for even coverage. I've seen cakes stick when people skip this step or use too little grease.
For extra insurance, line the pan with parchment paper cut to fit—just make sure to grease the paper too. The cake should release cleanly when ready to cool.
Nutrition facts
Frequently asked questions
Why does this chocolate sheet cake stay moist longer than others?
The secret lies in the inverted cooling method—baking the cake upside down preserves moisture by preventing condensation from pooling on the top. Plus, the precise ratio of melted butter to cocoa powder creates a dense yet tender crumb that resists drying out. Even after 5 days, slices stay rich and fudgy!
Can I substitute vegetable oil for butter in this recipe?
You can replace up to half the butter (about 0.5 cup) with vegetable oil, but the texture will be slightly less tender. The butter adds richness and helps create that signature fudgy layer. For best results, stick to the original ratio—it’s worth the effort for that restaurant-quality bite!
How do I know when the cake is fully baked?
Insert a toothpick into the center—it should come out with moist crumbs but no wet batter. Bake for 30-35 minutes at 350°F, but start checking at 30 minutes to avoid overbaking. The edges may pull away slightly, but the center should spring back when gently pressed.
What’s the best way to store leftovers?
Wrap the cake tightly in plastic wrap at room temperature for up to 5 days, or refrigerate for 7 days if you prefer. For longer storage, freeze individual slices in airtight containers for up to 3 months. Reheat wrapped slices at 300°F for 8-10 minutes to restore freshness.
Can I make this cake in a different pan size?
For a 9x13-inch pan, the recipe is perfect, but you can scale it down to a 9x9-inch square pan by reducing baking time to 25-30 minutes. For larger pans (like 10x15-inch), increase batter by 25% and bake for 35-40 minutes). Adjust times based on your oven—always check with a toothpick!