Sour Cream Chocolate Cake Recipe

This sour cream chocolate cake is a two layer 8 inch cocoa cake made with ½ cup of sour cream, oil, and a cup of boiling water or hot coffee, then filled and covered with a semi-sweet chocolate ganache. It bakes at 350°F for 30 to 35 minutes, takes about 2 hours from start to finish including cooling and setting, and serves 12.

The batter is mixed by hand in two bowls, no mixer needed. It ends up very thin, and that is exactly what keeps the crumb soft for days.

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What Sour Cream Does in Chocolate Cake

Sour cream brings fat and acid at the same time. The fat coats the flour and keeps the crumb tender, and the acid gives the baking soda something to react with, so the layers rise evenly. Its mild tang also takes the edge off the cocoa, which is why the cake tastes rich rather than flat or bitter.

Use full fat sour cream from the store. Light or fat free versions carry more water and less of the fat that keeps the cake moist. If you like making it yourself, my homemade sour cream works the same way. Out of sour cream? These swaps work, measured the same:

• Full fat Greek yogurt: the closest swap; the cake comes out slightly firmer
• Plain full fat yogurt: a little thinner, still tender
• Buttermilk: works, but the batter is even thinner, so the layers bake a touch flatter

Bring the sour cream, milk and eggs to room temperature before you start. Cold sour cream stays in small lumps in the oil mixture.

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Dutch-Processed or Natural Cocoa, Coffee or Water?

Dutch-processed cocoa gives a darker, smoother cake with a rounder chocolate taste, and it is my first choice here. Natural cocoa also works in this recipe, because it has both baking soda and baking powder to balance either kind. The cake will be a little lighter in color and slightly sharper.

For the hot liquid, freshly brewed coffee makes the chocolate taste deeper without making the cake taste of coffee. Boiling water gives a milder, sweeter chocolate cake and is the one to use for children. Fresh coffee has more aroma than instant.

Sift the cocoa with the flour, sugar, baking powder, baking soda and salt. Cocoa clumps, and those clumps stay as dry pockets in a batter this loose.

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Why This Chocolate Batter Looks So Thin

Whisk the eggs, milk, sour cream, oil and vanilla together until smooth, pour them into the dry ingredients, and stir with a spatula or wooden spoon until no flour streaks remain. At this point the batter is thick. A spoon keeps you from overmixing it.

Now pour in the cup of boiling water or hot coffee slowly, whisking the whole time. The hot liquid blooms the cocoa, which brings out its flavor, and dissolves the sugar. The batter turns thin and glossy, about as pourable as heavy cream.

That is right. Do not add flour to thicken it, or the cake will bake up dry and dense. Pouring the hot liquid slowly keeps the eggs from cooking in the bowl.

Divide the batter between two greased, parchment lined 8 inch pans. Use pans at least 2 inches deep, because thin batter rises well. Tap each pan on the counter a few times to release large air bubbles.

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Checking the Cocoa Layers at 30 Minutes

Bake at 350°F for 30 to 35 minutes and check at 30. The layers are done when a toothpick in the center comes out clean or with a few moist crumbs. Wet batter on the toothpick means a few more minutes. The tops should spring back when pressed lightly, and the edges should just pull away from the pan.

Cool the cakes in their pans for 10 minutes, then turn them out onto a wire rack. Let them cool completely before the ganache goes on. On a warm cake it slides off and soaks in instead of setting.

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Semi-Sweet Ganache for the Filling and Drip Top

The ganache is 2 cups (340g) of finely chopped semi-sweet chocolate and 1 cup (240ml) of heavy cream, about 1.4 parts chocolate to 1 part cream by weight. That is thick enough to spread between the layers once it sets, but still loose enough to drip down the sides. Use a bar rather than chocolate chips. Chips contain stabilizers that stop them melting smoothly.

Heat the cream until it just begins to simmer, pour it over the chocolate, and leave it alone for 3 to 5 minutes. Then whisk gently from the center out until smooth and glossy. Stir in the tablespoon of butter if you want extra shine. Let it cool at room temperature for 20 to 30 minutes until it is spreadable, like soft peanut butter. The fridge sets the edges before the middle.

• Too thin: wait another 10 minutes and stir.
• Too firm: warm it in the microwave for 5 to 10 seconds and stir.
• Grainy or oily: it split. Whisk in a tablespoon of warm cream, starting in the center, until it turns glossy again.

Spread a thick layer over the first cake, set the second on top, and pour the rest over so it runs down the sides. Swirl the top with an offset spatula or the back of a spoon. For more ganache ratios, see my chocolate ganache recipe. For a fluffier filling between the layers, my chocolate mousse filling for cakes also works with this cake.

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Sunken, Dense, or Dry Chocolate Layers

• Dry cake: almost always overbaked. Check at 30 minutes, and check your oven with an oven thermometer.
• Dense layers: the batter was overmixed after the flour went in, or flour was added to thicken the thin batter.
• Sunken center: old baking soda or powder, or the cake came out underbaked and collapsed as it cooled.
• Domed or cracked tops: usually an oven running hot. Level the tops with a serrated knife; the ganache hides the rest.

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How Long Sour Cream Chocolate Cake Stays Moist

Covered tightly, the cake keeps at room temperature for 2 days. In the fridge it lasts up to 5 days, but the ganache firms and the crumb tastes duller cold, so let slices sit out for 20 to 30 minutes before serving.

The layers can be baked a day ahead and kept tightly wrapped at room temperature before frosting. Unfrosted layers also freeze for up to 2 months, wrapped well. Thaw them overnight in the fridge, then add the ganache.

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Swaps and Add-Ins for This Cocoa Cake

• Almond note: add ½ teaspoon almond extract with the vanilla.
• Darker cake: replace half the cocoa with dark cocoa powder.
• Chips: fold 1 cup of mini chocolate chips into the finished batter.
• Different frosting: sour cream frosting or dark chocolate buttercream instead of ganache, or whipped cream and berries for a lighter cake.
• Taller cake: double the recipe and bake four layers.

For a filling between the layers, my chocolate cake filling also uses sour cream. If you like cocoa cakes with coconut, try my moist chocolate coconut cake, and for a fruit version, the chocolate cake with cherry pie filling.

Pin this sour cream chocolate cake to your chocolate cake board so it is there for the next birthday. If you made it with yogurt or tried one of the add-ins, tell me in the comments how it went.