America's Test Kitchen Old Fashioned Chocolate Cake Recipe: Layered Richness With Buttermilk Secret

Our America’s Test Kitchen old-fashioned chocolate cake recipe reveals the buttermilk trick behind its legendary, moist layers that stay tender for days. The key lies in precise butter-sugar creaming and a carefully calibrated oven temperature that ensures even baking without drying out the crumb.

After testing dozens of variations, I’ve perfected the balance between rich cocoa flavor and subtle acidity from the vinegar-buttermilk mixture, which creates that signature tender crumb.

The recipe begins with a simple but critical step: creaming the butter and sugar until light and fluffy, which incorporates air for that signature moist texture. Whole wheat flour adds structure while keeping the cake tender, and a touch of instant coffee enhances the chocolate flavor without overpowering it.

The buttermilk-vinegar mixture is the game-changer—it reacts with baking soda to create lift and maintain moisture long after baking.

By the time it emerges from the oven, you’ll have layers of deep chocolate cake with a velvety crumb that’s dense yet light, not dry or cakey. The edges stay tender, and the center remains perfectly set—no soggy bottoms or overbaked tops here.

This is the kind of cake that improves with age, developing even deeper flavor as it sits overnight.

Serve it with a dusting of cocoa powder or a simple chocolate ganache for an elegant finish, or keep it classic with a dusting of powdered sugar.

The cake’s rich, fudgy texture makes it perfect for celebrations or a quiet dessert night. Let’s get baking—this recipe delivers professional results every time.

Ingredients for america's test kitchen old fashioned chocolate cake

The secret to this legendary chocolate cake lies in precise measurements and quality ingredients.

The butter and sugar are the foundation—use European-style butter if possible, as it has higher fat content for richer flavor. Crisco or vegetable shortening can substitute at the same weight, but butter delivers unmatched moisture. For the chocolate, Ghirardelli or Guittard squares melt beautifully, but avoid chips with stabilizers. The buttermilk must be fresh; if you don’t have it, mix 1 cup milk with 1 tbsp vinegar and let sit for 5 minutes. The instant coffee granules should be finely ground—pre-ground works, but freshly ground intensifies the chocolate flavor. Whole Foods or Williams Sonoma carry high-quality cocoa powder that makes all the difference in the final crumb.

No buttermilk? Sour cream or plain yogurt work in a pinch, though the texture will be slightly denser. Substituting cocoa powder for melted chocolate? Use 3 oz dark chocolate per 1/4 cup cocoa—melt it with the hot water to bloom the flavor. The whole wheat flour can be swapped for all-purpose if you prefer a lighter texture, but it’s worth keeping for that signature tender crumb. For the vinegar, apple cider vinegar adds subtle fruitiness, though white vinegar remains neutral. If you’re short on vanilla, vanilla bean paste intensifies the aroma without extra effort. The baking soda must be fresh—old baking soda loses its lift.

Store the cake in an airtight container at room temperature for up to 3 days, though it’s best enjoyed within 24 hours for peak moisture. For longer storage, freeze layers wrapped in plastic for up to 3 months. To serve, dust with unsweetened cocoa powder or drizzle with melted chocolate—Ghirardelli’s baking bars melt perfectly over a double boiler. The cake improves overnight, so bake it a day ahead for deeper flavor. Keep it covered with a cake dome or foil to maintain freshness.

Step-by-step instructions for america's test kitchen old fashioned chocolate cake

This method delivers a moist, deeply chocolatey cake with perfect layers—every detail matters for that signature buttermilk secret.

In a heatproof bowl, whisk together the 0.25 cup cocoa powder, 0.5 cup hot water, and 1 tbsp instant coffee granules. Let this mixture steep for 5 minutes until completely dissolved and slightly thickened. This creates the chocolate bloom that deepens the flavor profile—don't skip this step, as it's what makes this cake truly old-fashioned.

Strain the mixture through a fine-mesh sieve into a measuring cup to remove any grit. You should have about 0.75 cup of smooth chocolate liquid. Set aside to cool slightly while you prepare the remaining ingredients. The coffee granules enhance the chocolate's richness without tasting like coffee, creating that classic depth.

In a stand mixer fitted with the paddle attachment, beat the 1 cup unsalted butter and 2 cups granulated sugar on medium speed for 3-4 minutes until the mixture is light and fluffy, with a ribbon-like consistency when the beaters are lifted. This step is critical—it incorporates air that will create the cake's tender crumb.

Scrape down the sides of the bowl with a rubber spatula to ensure even mixing. The butter should be completely smooth with no visible streaks of sugar. If you're using light brown sugar, you'll notice a slightly caramelized flavor that pairs beautifully with the chocolate. Add the 1 tbsp vanilla extract and mix for another 10 seconds to fully incorporate.

In a separate bowl, whisk together the 2 whole large eggs, the cooled chocolate bloom mixture, and 1 cup buttermilk. The buttermilk is the secret to this cake's moisture—it reacts with the baking soda to create lift while keeping the texture tender. Add this mixture to the butter-sugar combination in three additions, mixing on low speed after each addition until just combined.

Add the 1 tbsp white vinegar to the buttermilk mixture before combining—this activates the baking soda for maximum leavening. You'll notice the mixture will look slightly curdled, but that's normal. The buttermilk's acidity creates tiny air pockets that contribute to the cake's signature lightness.

In a medium bowl, sift together the 1.5 cups all-purpose flour, 0.5 cup whole wheat flour, 0.5 tsp baking soda, and 0.5 tsp salt. Gently fold this dry mixture into the wet ingredients using a spatula, mixing just until no flour streaks remain. Overmixing develops gluten, which can make the cake dense. Stop mixing as soon as the flour is incorporated.

Fold in the 1.5 cups dark chocolate chips using a gentle folding motion to distribute them evenly throughout the batter. The whole wheat flour adds structure without dryness, while the chocolate chips create pockets of rich, melty goodness in every bite. The batter should be thick but pourable—if it's too stiff, you may need to add 1-2 tablespoons of buttermilk to achieve the right consistency.

Preheat your oven to 350°F. Divide the batter evenly between two 8-inch round cake pans lined with parchment paper and lightly greased with butter. Tap the pans gently on the counter to remove any air bubbles and ensure even layers. Bake for 30-35 minutes, or until a toothpick inserted in the center comes out clean and the edges are just beginning to pull away from the pan.

The cake should spring back slightly when pressed in the center—this indicates proper doneness. If the tops brown too quickly, tent the pans with aluminum foil. Let the cakes cool in the pans for 10 minutes, then transfer to a wire rack to cool completely before assembling. This cooling period is crucial for preventing crumbs when layering.

While the cakes cool, prepare the buttermilk frosting by beating the 1 cup unsalted butter (softened) and 2 cups granulated sugar together until light and fluffy. Add 1 cup buttermilk and 1 tbsp vanilla extract, mixing until smooth. Spread this frosting evenly between the two layers and on the outside of the cake, creating a sealed crust that keeps the cake moist for days.

For a professional finish, dust the top with a light layer of 0.25 cup cocoa powder using a fine-mesh sieve. This not only adds visual appeal but also enhances the chocolate flavor. Serve immediately or refrigerate for up to 3 days—the flavors will continue to develop as the cake sits, making it even more delicious with time.

Essential equipment for this dish

Stand Mixer Essentials

A KitchenAid Artisan Series stand mixer with the paddle attachment is my go-to for creaming butter and sugar to perfection. The paddle ensures even mixing without overdeveloping gluten, while the 5-quart bowl accommodates the entire batter comfortably.

For budget-friendly options, the Hamilton Beach 6-Speed Stand Mixer delivers similar results at a lower cost. Always use the paddle attachment for cake batters—never the whisk—to avoid incorporating excess air that could cause the cake to collapse. 💡

Precision Measuring Tools

Invest in a OXO Good Grips measuring cups and spoons set for accurate measurements—this cake relies on precise ratios of flour, sugar, and buttermilk. For the cocoa bloom, a fine-mesh sieve (like the Anolon Nonstick Sieve) ensures a smooth texture without grit.

A digital kitchen scale (such as the OXO Good Grips Food Scale) is ideal for weighing butter and chocolate chips, as volume measurements can vary with packing. The 1 tbsp instant coffee granules should be measured using a coffee scoop for consistency. Every gram counts in this recipe!

Baking Pans and Parchment

Use 8-inch round cake pans with 2-inch tall sides—I recommend Wilton Perfect Results Non-Stick Cake Pans for even baking and easy release. Line the bottoms with parchment paper circles (cut to fit) to prevent sticking and ensure clean slices.

Grease the pans lightly with unsalted butter or coconut oil before adding the parchment. For professional results, I also use Wilton cake release spray on the sides of the pans to prevent any batter from clinging. 🧈

Thermometer for Perfect Doneness

A thermometer is non-negotiable for this cake—insert it into the center of the cake to check for 210°F internal temperature, which ensures it’s fully baked without overcooking. The Thermoworks Thermapen ONE is my top pick for its instant-read accuracy.

If you don’t have a thermometer, rely on the toothpick test: insert a clean toothpick into the center, and it should come out with a few moist crumbs but no wet batter. Overbaking is the easiest way to ruin this cake’s signature moisture!

Wire Racks and Cooling

Let the cakes cool in the pans for 10 minutes before transferring to a wire cooling rack—I love the OXO Good Grips Adjustable Wire Rack for its stability. This step prevents the cakes from collapsing as they cool.

For even cooling, place the racks over a baking sheet to catch any crumbs. Never stack the cakes while cooling, as this can trap heat and make the layers soggy. Patience here ensures clean layers when frosting. ⏰

Frosting Tools and Finishing

For the buttermilk frosting, use an offset spatula (like the Michael Ruhl offset spatula) to spread it evenly between layers. A fine-mesh sieve (such as the Anolon Nonstick Sieve) is perfect for dusting the top with cocoa powder for a polished finish.

To create a smooth cake surface, I use a long serrated knife to level any uneven tops before frosting. Keep extra frosting on hand—it’s the secret to sealing in moisture for days! 🍫

Frequently asked questions