White Sheet Cake

CAKE

Place oven rack on the middle setting and preheat the oven to 350ºF (177ºC). Grease and flour (or use homemade cake release) a 9" x 13" baking pan. Set aside.
In a large bowl with a handheld mixer or the bowl of a stand mixer fitted with the paddle attachment, combine the flour, cornstarch, sugar, baking powder, and salt. Blend ingredients together on low until completely combined, about 1 minute.
2 cups (240g) all-purpose flour, 2 Tablespoons (15g) cornstarch, 1 and ¾ cups (350g) granulated sugar, 4 teaspoons baking powder, 1 teaspoon salt
Add the room temperature butter and beat mixture on low speed until it resembles sand (see photo in post text). Scrape down the sides and bottom of the bowl with a spatula and mix again on low for a few seconds until thoroughly combined.
12 Tablespoons (171g) unsalted butter
Combine the whole milk, egg whites, and vanilla extract in a large container with a spout (like a 2-cup glass measuring cup) and mix gently with a fork until blended.
1 cup (240mL) whole milk, 6 large egg whites3, 2 and ½ teaspoons vanilla extract
With the mixer speed on medium-low, add half of the milk mixture (about 1 cup) to the crumb mixture and mix until blended. Add the remaining milk mixture to the batter and beat again on medium-low until everything is incorporated. Turn the mixer off, scrape down the sides and bottom of the bowl with a spatula, and increase mixer speed to medium. Beat the batter for about 30 seconds until batter is smooth.
Pour the batter into the prepared cake pan. Bake cake for about 32-34 minutes or until a toothpick or cake tester inserted in the center comes out clean and the top is lightly browned. Remove from oven and allow cake to cool completely on a wire rack before frosting.

VANILLA BUTTERCREAM

In a large bowl with a handheld mixer or a stand mixer fitted with the paddle attachment, beat the the butter on medium-high until smooth, about 2 minutes.
½ cup (113g) unsalted butter
Reduce the mixer to low, then slowly add the powdered sugar and salt and mix until everything is combined. Add the vanilla extract and mix again.
2 cups (240g) powdered sugar, 1 teaspoon vanilla extract, ⅛ teaspoon salt
Slowly add the milk or cream, watching for and stopping at desired consistency. Add the salt, then increase the mixer speed to medium and beat until completely smooth.
1 to 2 Tablespoons (15-30mL) milk or cream
If after beating, the frosting is too stiff, add more cream. If it is too thin, add more powdered sugar, about 2 Tablespoons at a time. Turn off the mixer and use a spatula to stir the buttercream by hand to remove air bubbles and make it smooth and creamy. This usually takes about 3-5 minutes, but can take longer, especially if your mixer is very strong. Buttercream is ready to use right away.
Spread frosting evenly over cooled cake and decorate as desired. Store leftovers covered tightly at room temperature up to 4 days or in the refrigerator up to 1 week. Cake freezes well, up to 2 months. Thaw at room temperature.

Ingredients

CAKE

BUTTERCREAM

Instructions

CAKE

VANILLA BUTTERCREAM

Notes

Nutrition Disclosure