Yellow Sheet Cake with Chocolate Frosting

A tender, buttery yellow cake bakes in a 9-by-13-inch pan and gets a generous cocoa buttercream topping for potlucks and casual gatherings.

135 min

16 slices

Golden yellow sheet cake in a pan with thick chocolate frosting spread in soft swirls.

Ingredients

2 1/2 cups all-purpose flour

2 1/2 tsp baking powder

1 tsp fine salt

1 cup unsalted butter, softened, including 1 tbsp for the pan

1 3/4 cups granulated sugar

4 large eggs, at room temperature

2 tsp vanilla extract for the cake

1 cup whole milk, at room temperature

1/2 cup unsalted butter, softened for the frosting

2/3 cup unsweetened cocoa powder

3 cups confectioners' sugar

1/3 cup whole milk for the frosting

1 tsp vanilla extract for the frosting

1/4 tsp fine salt for the frosting

Equipment

9-by-13-inch baking pan · Stand mixer or hand mixer · Mixing bowls · Whisk · Cooling rack · Offset spatula

Wait for a cool crumb

The cake must be fully at room temperature before frosting; warmth can soften the buttercream and pull crumbs into the topping.

Serve soft and tender

Room-temperature slices have the softest crumb and easiest-to-spread frosting.

Prepare and mix

01. Heat the oven to 350 F with a center rack, then grease a 9-by-13-inch pan using 1 tbsp from the cake butter.

02. Whisk flour, baking powder, and fine salt until the leavener is evenly distributed.

03. Beat the remaining cake butter and granulated sugar until pale and fluffy, scraping the bowl for an even cream.

04. Add the room-temperature eggs one at a time, then mix in the cake vanilla until the batter looks cohesive.

Complete and bake

05. On low speed, alternate the flour mixture and whole milk, beginning and ending with flour; stop as soon as no dry streaks remain.

06. Spread batter evenly in the pan and bake at 350 F for 32 to 36 minutes, until the center springs back and a tester has no wet batter.

Cool and frost

07. Cool in the pan for 15 minutes, then leave it on a rack until completely at room temperature, about 45 minutes more.

08. While the cake cools, beat frosting butter, sifted cocoa, and confectioners' sugar; blend in frosting milk, vanilla, and salt until spreadable.

09. Spread the buttercream edge to edge only after the cake is fully cool, keeping the crumb intact.

Serve and store

10. Cut into 16 portions and serve at room temperature; cover leftover cake tightly and store at room temperature for up to 3 days.