Fluffy Yellow Layer Cake

Instructions

Cook along with these step-by-step instructions

Launch Cook Mode

Adjust oven rack to middle position and heat oven to 350 degrees. Grease two 9-inch-wide by 2-inch-high round cake pans and line bottoms with parchment paper. Grease paper rounds, dust pans with flour, and knock out excess. Whisk flour, baking powder, baking soda, salt, and 1 1/2 cups sugar together in large bowl. In 4-cup liquid measuring cup or medium bowl, whisk together melted butter, buttermilk, oil, vanilla, and yolks.
In clean bowl of stand mixer fitted with whisk attachment, beat egg whites at medium-high speed until foamy, about 30 seconds. With machine running, gradually add remaining 1/4 cup sugar; continue to beat until stiff peaks just form, 30 to 60 seconds (whites should hold peak but mixture should appear moist). Transfer to bowl and set aside.
Add flour mixture to now-empty mixing bowl fitted with whisk attachment. With mixer running at low speed, gradually pour in butter mixture and mix until almost incorporated (a few streaks of dry flour will remain), about 15 seconds. Stop mixer and scrape whisk and sides of bowl. Return mixer to medium-low speed and beat until smooth and fully incorporated, 10 to 15 seconds.
Using rubber spatula, stir 1/3 of whites into batter to lighten, then add remaining whites and gently fold into batter until no white streaks remain. Divide batter evenly between prepared cake pans. Lightly tap pans against counter 2 or 3 times to dislodge any large air bubbles.
Bake until cake layers begin to pull away from sides of pans and toothpick inserted into center comes out clean, 20 to 22 minutes. Cool cakes in pans on wire rack for 10 minutes. Loosen cakes from sides of pans with small knife, then invert onto greased wire rack and peel off parchment. Invert cakes again and cool completely on rack, about 1 1/2 hours. *This recipe was developed using dark cake pans. If you're using light-colored cake pans, test the cake after 25 minutes.

CHOCOLATE FROSTING

In food processor, process butter, sugar, cocoa, and salt until smooth, about 30 seconds, scraping sides of bowl as needed. Add corn syrup and vanilla and process until just combined, 5 to 10 seconds. Scrape sides of bowl, then add chocolate and pulse until smooth and creamy, 10 to 15 seconds.

Recipe Tip

Frosting can be used immediately or up to 3 hours in advance. For longer storage, refrigerate the frosting, covered, and let it stand at room temperature for 1 hour before using.

TO FROST

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.
Recipe Tip
This cake can be assembled and refrigerated for up to 1 day. Bring to room temperature before serving. If you prefer, the cooled cakes can be wrapped tightly in plastic wrap and kept at room temperature for up to 1 day. Wrapped tightly in plastic, then aluminum foil, cakes can be frozen for up to 1 month. Defrost cakes at room temperature before unwrapping and frosting.