Key Lime Sheet Cake Recipe

Key Lime Sheet Cake brings the tropical tang of key lime pie to a crowd-pleasing, easy-to-slice cake—ideal for picnics, potlucks, or celebrations.

Featuring a moist, fluffy crumb baked over a buttery graham cracker crust, this cake is topped with creamy, zesty key lime frosting and finished with classic garnishes.

It’s a refreshing change from the usual desserts and offers the distinctive tartness of key limes in every bite. This recipe is designed to help bakers of any skill level achieve a perfect balance of citrus flavor, moist texture, and show stopping appearance.

Ingredients Checklist

Before baking, gather these essentials for the best texture and flavor. This list covers the crust, cake, frosting, and decoration options.

• For the Graham Cracker Crust:

  • 1¼ cups graham cracker crumbs

  • ¼ cup granulated sugar

  • 5 tablespoons unsalted butter, melted

• For the Key Lime Sheet Cake:

  • 1 cup unsalted butter, softened

  • 2 cups granulated sugar

  • 3 large eggs, room temperature

  • ½ cup sour cream or plain Greek yogurt

  • ½ cup key lime juice (fresh or bottled)

  • 1 tablespoon key lime zest

  • 2 teaspoons vanilla extract

  • 2¼ cups all-purpose flour, sifted

  • 1 teaspoon baking soda

  • 1 teaspoon baking powder

  • ½ teaspoon salt

  • ½ cup whole milk, room temperature

• For the Key Lime Frosting:

  • ½ cup unsalted butter, softened

  • 8 ounces cream cheese, softened

  • 4 to 4½ cups powdered sugar, sifted

  • 2 tablespoons key lime juice

  • 1 tablespoon key lime zest

  • 1 teaspoon vanilla extract

  • Pinch salt

• For Garnish:

  • Extra key lime zest

  • Thin lime slices or wedges

  • Graham cracker crumbs

  • Edible flowers or mint leaves (optional for presentation)

• Essential Equipment:

  • 13×9-inch baking pan

  • Parchment paper or nonstick spray

  • Stand mixer or hand mixer

  • Mixing bowls and spatulas

  • Microplane or zester

  • Wire cooling rack

  • Offset spatula

Step-by-Step Instructions

Follow these comprehensive steps for a perfectly layered and flavorful Key Lime Sheet Cake.

• Preheat oven to 350°F (175°C). Grease a 13×9-inch pan and line with parchment if desired.

• In a small bowl, combine graham cracker crumbs, sugar, and melted butter for the crust. Press evenly into the bottom of the prepared pan. Bake for 8–10 minutes until golden and fragrant. Allow to cool while preparing the cake batter.

• In a large bowl, cream butter and sugar together until light and fluffy, 3–4 minutes. Add eggs one at a time, mixing well after each addition. Scrape bowl as needed.

• Mix in sour cream, key lime juice, key lime zest, and vanilla until fully incorporated.

• In a separate bowl, whisk together flour, baking soda, baking powder, and salt. Add half the dry ingredients to the wet mixture, followed by half the milk. Repeat with remaining flour mixture and milk, mixing until just combined.

• Pour cake batter over the cooled crust, smoothing the top. Bake for 28–34 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs. Avoid overbaking.

• Cool cake in the pan for 20 minutes, then transfer to a rack to cool completely before frosting.

• For the frosting, beat softened butter and cream cheese together until smooth and creamy. Add key lime juice, zest, vanilla, and salt, mixing to combine. Gradually beat in powdered sugar until fluffy and spreadable.

• Once cake is fully cooled, spread frosting in an even layer using an offset spatula.

• Sprinkle with extra lime zest, graham cracker crumbs, and garnish with lime slices or edible flowers for a decorative finish.

• Chill cake for 30 minutes before slicing for cleaner edges and intensified flavor.

Tips for Perfect Results

A few extra pointers ensure a reliably moist, tangy, and bakery-worthy sheet cake.

• Use room temperature ingredients for a smooth, evenly textured batter and frosting.

• For the most authentic flavor, use fresh key limes if available; Persian limes are a fine substitute but may require slight adjustment to tartness.

• Don’t skip the graham cracker crust—it adds structure and a true “key lime pie” element.

• Sift dry ingredients to avoid lumps and achieve a delicate crumb.

• If the cake browns too quickly, tent loosely with foil for the last 10 minutes.

• Chill the cake after frosting to help flavors meld and improve slicing.

• For extra zing, add a touch of key lime zest to the frosting and as a final garnish.

• Always zest limes before juicing for best results.

Serving Suggestions

Here are several ways to present and enjoy this cake, whether for a casual gathering or special event.

• Serve cold or at cool room temperature for the most refreshing texture.

• Add a dollop of whipped cream or a scoop of coconut ice cream on each slice for a tropical flair.

• Top each piece with a thin lime wheel and a sprinkle of graham crumbs for a bakery finish.

• For parties, pre-slice and arrange on a large platter with fresh berries for color contrast.

• Pair with herbal iced tea or a tangy lemonade for the perfect summer dessert.

Final Thoughts

Key Lime Sheet Cake is the ultimate answer for bakers seeking the bright, bold flavors of key lime pie in a format that feeds a crowd and is easy to serve.

By combining a sturdy graham crust, moist citrus cake, and luscious cream cheese frosting, you get all the best aspects of the classic pie with the simplicity of a sheet cake.

With plenty of make-ahead and storage options, this recipe is perfect for celebrations year-round. Enjoy sharing a taste of the tropics—one slice at a time.