Chocolate Birthday Layer Cake Recipe

An easy and moist chocolate layer cake with smooth chocolate frosting.

A frosted chocolate birthday cake on a stand, studded with festive candles.

Serious Eats / Yvonne Ruperti

Why It Works

  • Using vegetable oil in the batter makes the cake extremely moist.
  • Flavoring the cake with cocoa and espresso powder gives it a deep, chocolaty flavor. Sour cream adds a welcome lactic tang.
  • The frosting comes together quickly and without the need for chilling prior to assembling the cake.
  • Adding corn syrup to the frosting ensures a smooth result with no grittiness.

When the anticipation of decent presents and being another year older have long since evaporated like the memories of that first kiss in the back of the movie theater, I say thank god at least for birthday cake.

This cake is the perfect party cake. Dark, dewy, cocoa-espresso cake layers nest in heavy swathes of bittersweet chocolate frosting. Sitting tall and pretty, decked out in creamy swirls of chocolate, this cake dares you to resist. But you won't, and as you dig your fork into a slice, the velvety cake gently yields under the satiny icing.

But this cake is by no means fancy or elaborate. It's a basic cake that smacks of a simple, moist Betty Crocker cake—except this one's real. And I'm sure I don't have to tell you that this cake isn't just for birthdays. Every cook should have an easy-to-make, star chocolate cake to pull out of their recipe box at a moment's notice, and today I'm offering up my all-time favorite.

And did I say easy? You bet I did. This recipe is a lickety-split "dump and stir" method. Simply whisk the wet ingredients into the dry, and in the oven it goes.

Cocoa, espresso, and tangy sour cream flavor the cake. I also swear by vegetable oil in all my chocolate cakes—nothing makes a chocolate cake more moist. For the frosting, the best tasting, quickest frosting, hands down, is based on the very first recipe that I developed for Cook's Illustrated. Unlike chocolate ganache (which you have to chill until it sets), you can frost your cake as soon as you make it. And unlike most quick frostings (which are gritty from confectioners' sugar), swapping some of the sugar for corn syrup keeps it creamy. My chocolate cravings have gotten bigger lately, so this time around I tweaked the original by making it less sweet and more chocolaty. (For the best results use a high-quality bittersweet chocolate.)

To assemble, just spread a dollop of frosting in between the two cakes and sandwich them together. If you own a cake wheel and a spatula, you can spin this cake to professional perfection. Otherwise, just do what grandma always did—use the back of a soup spoon to whirl the shiny icing into soft swirly tufts. Sprinkle on the technicolor sprinkles or sugar confetti, load it up with candles, and celebrate another year to eat cake.

February 2012

Recipe Facts

Active: 45 mins
Total: 2 hrs 30 mins
Serves: 12 to 14 servings

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Ingredients

For the Cake:

  • 1 1/2 cups all-purpose flour

  • 1/2 cup cocoa powder (see notes)

  • 1 1/4 teaspoons baking soda

  • 1/4 teaspoon salt

  • 1 1/4 cups granulated sugar

  • 1 1/4 cups sour cream

  • 2/3 cup vegetable oil

  • 2 large eggs

  • 1 teaspoon pure vanilla extract

  • 1 teaspoon instant espresso powder

For the Frosting:

  • 20 tablespoons unsalted butter, softened (see notes)

  • 1 cup confectioners' sugar

  • 3/4 cup plus 1 tablespoon cocoa powder

  • Pinch salt

  • 2/3 cup light corn syrup

  • 1 teaspoon pure vanilla extract

  • 10 ounces bittersweet chocolate, melted and cooled

Directions

  1. To Make the Cake: Adjust oven rack to middle position and preheat oven to 350°F (175°C). Line bottoms of two 9-inch cake pans with parchment paper and lightly coat the inside with non-stick pan spray (see notes). Sift flour, cocoa, baking soda, and salt into a large bowl; set aside. In a medium bowl, whisk sugar, sour cream, oil, eggs, vanilla, and espresso powder until smooth.

  2. Whisk wet ingredients into dry ingredients until smooth. Evenly divide into pans and bake until cake is just firm and toothpick inserted into center comes out with moist crumbs, about 25 minutes. Let cake cool in pans for 15 minutes, then remove cakes from pans to completely cool on wire rack, about 1 hour.

  3. Meanwhile, make the frosting: In a food processor, process butter, confectioners' sugar, cocoa, and salt until completely combined and smooth. Add corn syrup and vanilla and combine until smooth, scraping down sides of bowl as necessary. Add chocolate and process until just smooth. See notes.

  4. To Assemble the Cake: Place one cake (top side up) on a serving plate. Spread about 1 cup frosting onto cake. Place second cake (bottom side up) on top. Frost top and sides with remaining frosting. Use back of soup spoon to make swirls on cake. Decorate if desired and serve.

Special Equipment

Two 9-inch cake pans, parchment paper, food processor

Notes

Make sure to use natural cocoa. Do not use Dutch processed or the leavening of the cake may be affected.

8-inch cake pans may be used. Baking time may be longer.

Do not over-soften butter or the frosting will be too loose. It should yield lightly to the touch (about 60°F or 16°C).

If the chocolate is too warm, the frosting may be too loose. Just chill the finished frosting briefly until it thickens enough to spread.

Make-Ahead and Storage

This cake keeps at room temperature, covered, for 2 days. It can be made ahead and refrigerated. Bring to room temperature before serving.

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Nutrition Facts (per serving)
646 Calories
43g Fat
60g Carbs
7g Protein
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Nutrition Facts
Servings: 12 to 14
Amount per serving
Calories 646
% Daily Value*
Total Fat 43g 55%
Saturated Fat 20g 99%
Cholesterol 83mg 28%
Sodium 194mg 8%
Total Carbohydrate 60g 22%
Dietary Fiber 5g 19%
Total Sugars 39g
Protein 7g
Vitamin C 0mg 1%
Calcium 55mg 4%
Iron 7mg 39%
Potassium 225mg 5%
*The % Daily Value (DV) tells you how much a nutrient in a food serving contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.
(Nutrition information is calculated using an ingredient database and should be considered an estimate.)