Standard Sheet Cakes Recipe

Prepare

Preheat oven to 350°F (175°C). Grease two standard full sheet pans (18 x 13 inches) or three half-sheet pans (13 x 18 inches) with vegetable oil or spray, then line with parchment paper if desired. Bring eggs, milk, and butter to room temperature (about 20–30 minutes) for even mixing.

Dry ingredients

In a very large bowl or the bowl of a stand mixer, whisk together the all-purpose flour (6 cups), granulated sugar (4 cups), baking powder (6 tsp), baking soda (1 tsp), and fine salt (2 tsp) until homogenous.

Cream fats

In a separate large bowl or the stand mixer fitted with the paddle attachment, cream the room-temperature unsalted butter (2 cups) with the vegetable oil (1 cup) on medium speed until smooth and slightly pale, about 1–2 minutes.

Add eggs and vanilla

Add the eggs (8 large) one at a time to the creamed butter/oil mixture, beating briefly after each addition until incorporated. Add the vanilla extract (4 tbs) and mix until combined.

Combine wet and dry

With the mixer on low, add about one-third of the dry ingredients to the wet mixture, then half of the milk (1.5 cups). Repeat: another third of dry, remaining milk, then the last third of dry. Mix only until combined after each addition to avoid overdeveloping gluten. Scrape the bowl as needed.

Optional add-ins

If using optional add-ins: fold in cocoa powder (1 cup) at the dry-ingredient stage for a chocolate cake (reduce flour by 1 cup if using cocoa as a flour replacement), or gently fold in sour cream/buttermilk (1 cup) with one of the milk additions for extra moistness, or fold in chocolate chips/nuts (2 cups) at the end.

Portion & bake

Divide batter evenly between prepared sheet pans, smoothing the tops with an offset spatula. For half-sheet pans, bake at 350°F (175°C) for 20–25 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs. For full-sheet pans, bake 18–30 minutes depending on depth — check at 18 minutes and continue until done. Rotate pans halfway through for even browning.

Cool

Remove pans from oven and set on wire racks. Let cakes cool in pans 10 minutes, then run a knife around edges and invert onto racks or leave in pans to cool completely. For frosting, cool completely to room temperature (at least 1 hour) to avoid melting the buttercream.

Beat butter

In a clean bowl or stand mixer bowl fitted with the paddle attachment, beat the room-temperature unsalted butter (2 cups) on medium speed until light and fluffy, about 2–3 minutes.

Add sugar

Reduce speed to low and gradually add the powdered sugar (8 cups), about 1–2 cups at a time, letting it incorporate before adding more to avoid a powdered-sugar cloud. Scrape the bowl as needed.

Add liquid and flavor

Once the sugar is mostly incorporated, add the vanilla extract (2 tbs), fine salt (1 tsp), and 4 tablespoons of milk or cream. Increase mixer speed to medium-high and beat for 1–2 minutes until light and spreadable. If frosting is too stiff, add up to the remaining 2 tablespoons of milk, 1 tablespoon at a time. If too thin, add more powdered sugar 1/2 cup at a time.

Frosting the cake

If cakes are stacked or multiple layers are used, level cakes as needed. Place the bottom cake layer on a serving board or pan, add an even layer of buttercream using an offset spatula, then top with the next layer. For sheet cakes kept single-layer, spread an even coat of buttercream over the cooled cake. Smooth with a spatula or create decorative swirls. Dust with powdered sugar if desired.

Decorate as desired with piping, sprinkles, or nuts. For best texture, let frosted cake rest at room temperature for 30 minutes before slicing to allow frosting to set. Store covered at room temperature up to 2 days or refrigerate in an airtight container up to 5 days. If refrigerated, bring to room temperature before serving for best flavor and texture (about 1 hour).

Make-ahead: Bake cakes and freeze undecorated layers wrapped tightly in plastic and foil for up to 3 months. Thaw overnight in the refrigerator and bring to room temperature before frosting.