Key Lime Sheet Cake

Key Lime Sheet Cake is the perfect citrusy treat for any summer occasion. This refreshing dessert combines the tanginess of fresh lime with the soft, light texture of a buttermilk sheet cake, topped with a luscious lime frosting. It’s a simple yet elegant cake that’s sure to impress guests at a picnic, barbecue, or family gathering.

Why You’ll Love This Recipe

This Key Lime Sheet Cake is a refreshing twist on the classic buttermilk sheet cake. It boasts a soft and tender crumb from the perfect combination of buttermilk, butter, and oil. The fresh lime zest and juice lend a vibrant citrus flavor that shines through both the cake and frosting. The lime frosting is rich and creamy, with just the right amount of tang. Best of all, it’s a breeze to prepare, making it an ideal dessert for any event. Plus, the cake is super versatile—it can easily be doubled or halved depending on the number of servings needed. It’s a crowd-pleaser that everyone will love!

Ingredients

For the Cake:

1 3/4 cups granulated sugar
2 cups all-purpose flour
1/4 teaspoon salt
1/2 teaspoon baking soda
1/2 cup salted butter, melted
1/2 cup vegetable oil
Zest of 3 limes
1/4 cup fresh lime juice
3/4 cup boiling water
2 large eggs, beaten
1/2 cup buttermilk
1 teaspoon vanilla extract

For the Frosting:

1/2 cup salted butter, melted
4 cups powdered sugar
3 tablespoons whole milk
1 teaspoon vanilla extract
1-2 tablespoons lime juice
Lime zest for garnish

(Tip: You’ll find the full list of ingredients and measurements in the recipe card below.)

Directions

1. Preheat your oven to 400°F. Spray an 11×17-inch rimmed baking sheet with non-stick cooking spray.

2. In a large bowl, whisk together the sugar, flour, salt, and baking soda.

3. Add the melted butter, vegetable oil, lime zest, lime juice, and boiling water to the dry ingredients, and whisk to combine.

4. Whisk in the beaten eggs, buttermilk, and vanilla extract. Mix until the batter is smooth.

5. Pour the batter into the prepared pan and bake for 11-13 minutes. The cake is done when the top springs back to the touch or when a toothpick inserted into the center comes out with a few moist crumbs.

6. While the cake is baking, prepare the frosting. In a medium bowl, whisk together the melted butter, powdered sugar, milk, vanilla extract, and lime juice until smooth. Add more lime juice if needed to reach your desired frosting consistency.

7. Once the cake has cooled slightly, spread the frosting on top. Garnish with extra lime zest and lime slices.

Servings and Timing

• Servings: 15

• Prep Time: 10 minutes

• Cook Time: 11 minutes

• Total Time: 21 minutes

Variations

• Gluten-Free: Use a gluten-free all-purpose flour blend to make the cake gluten-free.

• Dairy-Free: Replace the butter with a dairy-free option and use almond or oat milk instead of whole milk in the frosting.

• Tropical Twist: Add some shredded coconut to the batter for a tropical flavor boost.

• Extra Citrus: For a more intense lime flavor, you can add a bit of lime extract to the cake or frosting.

Storage/Reheating

• Storage: Store the cake in an airtight container at room temperature for up to 3 days. It will stay fresh and moist for several days.

• Freezing: The cake freezes well! Wrap it tightly in plastic wrap and store it in an airtight container in the freezer for up to 3 months. Thaw it at room temperature before serving.

• Reheating: To warm up slices, pop them in the microwave for about 10-15 seconds, or heat in the oven at 300°F for about 5 minutes.

FAQs

How do I know when the Key Lime Sheet Cake is done baking?

The cake is done when the top springs back when you gently press it or when a toothpick inserted into the center comes out with a few moist crumbs.

Can I use bottled lime juice instead of fresh lime juice?

While fresh lime juice is recommended for the best flavor, bottled lime juice can be used in a pinch.

Can I make this cake ahead of time?

Yes, you can make the cake a day ahead and store it covered at room temperature. Frost it just before serving.

What can I use instead of buttermilk?

If you don’t have buttermilk, you can substitute it with 1/2 cup of milk mixed with 1/2 tablespoon of white vinegar or lemon juice. Let it sit for 5 minutes before using.

How long does the cake stay fresh?

The cake will stay fresh at room temperature for up to 3 days, or you can freeze it for up to 3 months.

Can I make this into cupcakes instead of a sheet cake?

Yes, you can use the same batter to make cupcakes. Bake them at 350°F for about 15-18 minutes or until a toothpick comes out clean.

Is this cake overly sweet?

The cake itself is not overly sweet, with a subtle balance of sweetness from the frosting and the tang from the lime. If you prefer less sweetness, reduce the sugar in the frosting.

Can I add more lime zest for a stronger lime flavor?

Yes, feel free to increase the amount of lime zest in both the cake and frosting to suit your taste.

What’s the best way to store leftovers?

Store leftovers in an airtight container at room temperature for up to 3 days. Alternatively, you can freeze individual slices for later enjoyment.

Can I double the recipe for a larger crowd?

Absolutely! You can double the ingredients and bake in a larger pan, or make two sheet cakes. Adjust the baking time if necessary.

Conclusion

This Key Lime Sheet Cake is the ultimate refreshing dessert for any occasion, especially in the warmer months. Its light, citrusy flavor paired with a creamy lime frosting is sure to impress your friends and family. Quick and easy to prepare, it’s a delicious treat everyone can enjoy. Whether for a summer picnic or a sweet treat after dinner, this cake is a surefire hit!