Lemon Sheet Cake for a Crowd: Tender, Tangy, Foolproof

Mixing Method: Don't Overmix

Add the dry ingredients in three additions, alternating with the buttermilk. Start and end with the flour. Mix on low speed just until each addition is incorporated. Overmixing develops gluten, which makes the cake tough and dense. You want a smooth, thick batter that falls in ribbons from the spatula.

Baking and Doneness Cues

Bake at 350°F for 22–25 minutes. The cake is done when the top is golden brown, the edges pull away from the pan slightly, and a toothpick inserted in the center comes out with a few moist crumbs—not wet batter. If the toothpick is clean, you've gone a minute or two too long. The cake will continue to set as it cools.

Cool the cake in the pan on a wire rack for 10 minutes. Then lift it out using the parchment overhang and let it cool completely on the rack. This prevents the bottom from steaming and becoming soggy.

The Glaze: Simple and Foolproof

Sift the powdered sugar first to avoid lumps. Whisk in the lemon juice, milk, and vanilla until the glaze is smooth and thick but pourable—like honey. If it's too thick, add a drop more milk. Too thin, add a tablespoon more powdered sugar. Pour the glaze over the cooled cake and spread it gently to the edges. Let it set for 15 minutes before slicing. The glaze will form a thin, crackly shell that shatters slightly when you cut through it.

Slicing and Serving

Use a sharp serrated knife for the cleanest slices. Wipe the blade clean between cuts. For a party, cut the cake into 24 squares (4 rows by 6 rows). Each piece is about 3 inches wide—generous but not overwhelming. Garnish with fresh lemon zest curls or a few edible flowers if you want to dress it up.

Common Mistakes to Avoid

Don't skip the parchment paper. Without it, the cake can stick to the pan, especially around the edges. Don't open the oven door during the first 15 minutes of baking—the temperature drop can cause the cake to sink. And don't glaze the cake while it's still warm; the glaze will melt and soak in, leaving you with a sticky, uneven top instead of a glossy finish.