Fluffy Yellow Layer Cake

By MooK

Ingredients

• Cake
• 2 1/2 Cups (10 ounces) cake flour *
• 1 1/4 Teaspoons baking powder
• 1/4 Teaspoon baking soda
• 3/4 Teaspoon salt
• 1 3/4 Cups (12 1/4 ounces) granulated sugar
• 10 Tablespoons unsalted butter , melted and cooled
• 1 Cup buttermilk , room temperature * *
• 3 Tablespoons vegetable oil
• 2 Teaspoons vanilla extract
• 3 Large eggs , separated, plus 3 large yolks, room temperature * * *
• Pinch cream of tartar
• Frosting
• 20 Tablespoons (2 1/2 sticks) unsalted butter , softened
• 1 Cup (4 ouncs) confectioners' sugar
• 3/4 Cup (2 1/4 ounces) cocoa powder
• Pinch salt
• 3/4 Cup light corn syrup
• 8 Ounces milk chocolate , melted and cooled * * * *
• The ultralight texture of this cake demands soft cake flour. If you use all-purpose flour the cake will be tougher, drier, and denser.
• It’s important to bring the buttermilk and eggs to room temperature before using them.
• It’s important to bring the buttermilk and eggs to room temperature before using them.
• This frosting may be made with milk, semisweet, or bittersweet chocolate; we prefer a frosting made with milk chocolate for this recipe. Cool the chocolate to between 85 and 100 degrees before adding it to the butter mixture.

Preparation

Step 1

Prepare Cake

Adjust oven rack to middle position and heat oven to 350 degrees. Grease two 9‑inch round cake pans, line with parchment paper, grease parchment, and flour pans. Whisk 2 ½ cups cake flour, 1 ¼ teaspoons baking powder, ¼ teaspoon baking soda, ¾ teaspoon salt, and 1 ½ cups granulated sugar together in large bowl. Melt 10 tablespoons unsalted butter and cool to room temperature. Separate 3 large eggs into 2 bowls. Separate 3 more eggs, discarding whites and adding yolks to 1 bowl for total of 6 yolks. Bring eggs to room temperature.

In medium bowl, whisk together butter, 1 cup room temperature buttermilk, 3 tablespoons vegetable oil, 2 teaspoons vanilla extract, and egg yolks. Using stand mixer fitted with whisk, whip egg whites and pinch cream of tartar on medium-low speed until foamy, about 1 minute. Increase speed to medium-high and whip whites to soft billowy mounds, about 1 minute. Gradually add remaining 1/4 cup granulated sugar and whip until glossy, stiff peaks form, 2 to 3 minutes. Transfer to bowl and set aside.

Add flour mixture to now-empty bowl. With mixer on low speed, gradually pour in butter mixture and mix until almost incorporated (a few streaks of dry flour will remain), about 15 seconds. Scrape down bowl, then beat on medium-low speed until smooth and fully incorporated, 10 to 15 seconds. Using rubber spatula, stir one-third of whites into batter, then add remaining two-thirds whites and gently fold into batter until no white streaks remain. Divide batter evenly between prepared pans, smooth tops with rubber spatula, and gently tap pans on counter to release air bubbles. Bake cake until toothpick inserted in centers comes out clean, 20 to 22 minutes. Let cakes cool in pans on wire rack for 10 minutes. Remove cakes from pans, discard parchment, and let cool completely, about 2 hours, before frosting.

Prepare Frosting

Soften 20 tablespoons (2 ½ sticks) unsalted butter on counter. Melt 8 ounces milk chocolate and cool to between 85 and 100 degrees. Process softened butter, 1 cup confectioners’ sugar, ¾ cup cocoa, and pinch salt in food processor until smooth, about 30 seconds, scraping down bowl as needed. Add ¾ cup light corn syrup and 1 teaspoon vanilla extract and process until just combined, 5 to 10 seconds. Scrape down bowl, then add melted and cooled milk chocolate and process until smooth and creamy, 10 to 15 seconds.

Assemble Cake

Line edges of cake platter with 4 strips of parchment paper to keep platter clean. Place 1 cake layer on prepared platter. Place about 1 1/2 cups frosting in center of cake layer and, using large spatula, spread in even layer right to edge of cake. Place second cake layer on top, making sure layers are aligned, then frost top in same manner as first layer, this time spreading frosting until slightly over edge. Gather more frosting on tip of spatula and gently spread icing onto side of cake. Create billows by pressing back of spoon into frosting and twirling spoon as you lift away. Pull out pieces of parchment from beneath cake before serving.