If you’ve ever wondered what is a Key lime cake, you’re in for a refreshing, flavorful surprise. Bursting with the bright, tangy flavor of Key limes and balanced with a soft, sweet crumb, this cake is the ultimate dessert for spring brunches, summer birthdays, or anytime you crave something citrusy and satisfying.
Inspired by classic Southern baking and even rumored to be Oprah’s favorite Key lime cake, this recipe delivers creamy richness, vibrant citrus notes, and a melt-in-your-mouth texture. Let’s dive into how you can create this homemade delight in your own kitchen—with everyday ingredients and simple steps.
Ingredients List
Here’s everything you’ll need to make a homemade Key lime cake from scratch. Most of these ingredients are pantry staples!
For the Cake:
- 2 ½ cups all-purpose flour
- 2 tsp baking powder
- ½ tsp baking soda
- ½ tsp salt
- ¾ cup unsalted butter (softened)
- 1 ¾ cups granulated sugar
- 4 large eggs
- 1 tsp vanilla extract
- 1 Tbsp Key lime zest
- ½ cup fresh Key lime juice (about 10–12 Key limes)
- 1 cup buttermilk
For the Key Lime Cream Cheese Frosting:
- 8 oz cream cheese (softened)
- ½ cup unsalted butter (softened)
- 2–3 cups powdered sugar (sifted)
- 1 tsp vanilla extract
- 2 Tbsp Key lime juice
- Zest of 1 Key lime
Step-by-Step Instructions
Follow these simple instructions for a tender, flavorful cake that’s as beautiful as it is delicious.
Step 1: Prepare Your Pans & Preheat Oven
Preheat your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans or line them with parchment paper circles.
Step 2: Mix Dry Ingredients
In a medium bowl, whisk together flour, baking powder, baking soda, and salt. Set aside.
Step 3: Cream the Butter and Sugar
In a large mixing bowl, cream the softened butter and granulated sugar until light and fluffy (about 2–3 minutes using an electric mixer).
Step 4: Add Eggs and Flavorings
Add eggs one at a time, beating well after each. Mix in vanilla extract and Key lime zest.
Step 5: Combine with Lime Juice and Buttermilk
Mix the Key lime juice and buttermilk in a separate cup. Alternately add the flour mixture and lime-buttermilk mixture to the batter, beginning and ending with the dry ingredients. Mix until just combined.
Step 6: Bake
Divide batter evenly between the two pans. Bake for 25–30 minutes or until a toothpick inserted into the center comes out clean. Let cakes cool in pans for 10 minutes, then transfer to wire racks to cool completely.
Step 7: Make the Frosting
Beat cream cheese and butter until smooth. Add powdered sugar gradually, then mix in vanilla, lime juice, and zest. Continue beating until fluffy.
Step 8: Assemble and Frost
Place one cake layer on a serving plate, spread with frosting, then top with the second layer and frost the entire cake. Garnish with lime slices or zest if desired.
Expert Cooking Tips
- Fresh Key limes make a huge difference—avoid bottled juice if possible.
- Zest before juicing for maximum flavor with less effort.
- Don’t overmix the batter; stir just until combined to avoid a dense texture.
- For extra moisture, brush the layers with a little lime syrup before frosting.
- Chill the cake for 30 minutes before slicing—it helps the frosting set beautifully.
Ingredient Substitutions
No buttermilk? Mix 1 cup of milk with 1 Tbsp lemon juice or vinegar and let sit for 5 minutes.
No Key limes? You can substitute regular Persian limes, but the flavor will be less tart and floral. That said, if you’ve ever asked, “Can I use lime instead of lemon in cakes?”—yes, absolutely!
Additional Info
| Detail | Value |
|---|---|
| Prep Time | 20 minutes |
| Cook Time | 30 minutes |
| Total Time | 50 minutes + cooling |
| Servings | 12 |
| Difficulty | Easy to moderate |
| Freezer-Friendly | Yes (unfrosted layers only) |
Nutritional Information (Per Slice)
- Calories: ~430
- Total Fat: 21g
- Sugar: 38g
- Protein: 5g
- Carbs: 56g
Note: Values may vary depending on frosting thickness and ingredient brands.
Frequently Asked Questions (FAQ)
What is a Key lime cake?
A Key lime cake is a soft, moist dessert flavored with the tart juice and zest of Key limes. It usually includes a citrusy frosting for extra zing.
What is Oprah’s favorite Key lime cake?
Oprah has spotlighted several Southern-style Key lime cakes on her “Favorite Things” list, often highlighting rich, homemade versions with cream cheese frosting and bold lime flavor.
What is the difference between lime and Key lime?
Key limes are smaller, more aromatic, and have a tart-sweet flavor that’s bolder than regular limes. They’re a staple in Southern and tropical desserts like pies and cakes.
Can I use lime instead of lemon in cakes?
Yes! Limes—especially Key limes—can be used instead of lemons in most cake recipes to add a refreshing citrus kick.
Try This Delicious Key Lime Cake Today!
Whether you’re baking for a family celebration, a weekend treat, or just to satisfy a citrus craving, this Key lime cake recipe is a crowd-pleaser that’s easy to love. If you try it, leave a comment below, rate the recipe, or tag us on social media. We’d love to hear how yours turned out!