Key lime pie gets all the spotlight, but this key lime cake hits all the right notes. It plays on the sweet and tart flavors in key lime pie, but infuses them into a fluffy cake and a not-too-sweet cream cheese frosting. The cake layers get their velvety and tender texture through the reverse creaming method. And when all the elements come together, it’s a three-layer centerpiece perfect for celebrating any special occasion.
Do I Need to Use Key Limes?
Key limes are sometimes difficult to find, but if you can get your hands on them, they have a wonderfully puckery flavor that will impart a strong lime flavor. Visually, they tend to be smaller than standard limes and have thinner rinds, making them an extra-cute cake topper. If you can’t find key limes, standard limes (aka Persian limes) may be substituted.
The Secret to Super Moist and Fluffy Cake
The combination of butter, oil and sour cream in the recipe makes for a super-moist and fluffy cake. This recipe also calls for the reverse creaming method. This means that the dry ingredients are mixed before adding the wet ingredients to limit gluten development and reduce the chances of over-mixing.
Key Lime Cake
Serves 16; makes 1 (3-layer) 8-inch cake
For the Cake
- 8 tablespoons (1 stick) unsalted butter
- 3 large eggs
- Cooking spray
- 2 3/4 cups cake flour
- 2 1/4 teaspoon baking powder
- 3/4 teaspoon baking soda
- 3/4 teaspoon kosher salt
- 1 large key lime
- 1 3/4 cups granulated sugar
- 1/2 cup sour cream
- 1/4 cup neutral oil, such as canola
- 1 cup whole milk
For the Cream Cheese Frosting
- 3 sticks (12 ounces) unsalted butter
- 12 ounces cream cheese
- 1 large key lime
- 1/4 teaspoon kosher salt
- 1 pound (5 cups) powdered sugar
For Decorating (optional)
- 1 large key lime
Make the Cake
1. Place 1 stick unsalted butter and 3 large eggs on the counter. Let sit at room temperature until the butter is softened.
2. Arrange a rack in the middle of the oven and heat the oven to 350 F. Lightly coat the bottoms of 3 (8-inch) round cake pans with cooking spray. Line the bottom of each pan with a parchment paper round. Lightly coat the sides and bottom of the pans with cooking spray. (If you don’t have three pans, the cake can be baked in batches. Bake and cool the first batch of cakes as instructed. After removing the cakes from the pans to cool, wash and dry the pans and then prepare by spraying with cooking spray, lining the bottom with parchment and spraying once more. Pour the batter into the prepared pans and bake as instructed.)
3. Place 2 3/4 cups cake flour, 2 1/4 teaspoons baking powder, 3/4 teaspoon baking soda, and 3/4 teaspoon kosher salt in the bowl of a stand mixer (or large bowl if using an electric hand mixer). Mix on low speed with the paddle attachment until combined.
4. Finely grate the zest of 1 large key lime into the bowl. Add the butter and 1 3/4 cups granulated sugar. Beat with the paddle attachment on low speed until the mixture appears dry and sandy, about 2 minutes.
5. Place the eggs, 1/2 cup sour cream, and 1/4 cup neutral oil in a medium bowl and whisk to combine.
6. With the mixer on low speed, slowly pour the egg mixture into the flour mixture and beat until combined, about 40 seconds. With the mixer still on low speed, slowly pour in 1 cup whole milk and beat until combined, about 1 1/2 minutes.
7. Divide the batter evenly between the cake pans (about 440 grams or 1 3/4 cups each).
8. Bake until the tops are rounded and a tester inserted into the center comes out clean, 20 to 25 minutes. Meanwhile, wash and dry the mixer bowl and paddle attachment. Place the 3 sticks unsalted butter and 12 ounces cream cheese for the frosting in the bowl and let sit at room temperature to soften.
9. Place the pans on a wire rack and let the cakes cool slightly, about 10 minutes. Run a small offset spatula or paring knife around each cake to loosen. Flip each cake out and remove and discard the parchment. Flip again to be right-side up and place on the wire rack. Let cool completely, about 1 hour. Meanwhile, make the buttercream.
Make the Cream Cheese Frosting:
1. Finely grate the zest from 1 large key lime until you have 1 teaspoon. Juice the lime until you have 1 tablespoon.
2. Add the lime zest and 1/4 teaspoon kosher salt to the bowl of butter and cream cheese. Beat with the paddle attachment on medium speed until smooth, scraping the bowl as needed, about 2 minutes.
3. Add 1 pound (5 cups) powdered sugar and beat on low speed until combined, about 2 minutes. Add the lime juice and on low speed beat until combined.
To Assemble
1. Using a serrated knife, trim the tops of each cake to create a flat surface. Place one layer on a cake board on a cake turntable. Dollop 1 cup of the frosting onto the cake and spread into an even layer with an offset spatula, going all the way to the edges. Top with the second cake layer, then repeat spreading the same amount of frosting on this layer. Top with the last cake layer with the cut side facing down.
2. Using an offset spatula, spread and smooth a very thin layer of cream cheese frosting (called a crumb coat) over the top and sides of the cake. Refrigerate the cake until the crumb coat is set, 15 to 20 minutes.
3. Frost the entire cake with the remaining frosting. If decorating, thinly slice 1 large key lime into rounds, then cut the rounds in half to create half-moons. Decorate the cake with the lime slices.
Recipe Notes
Substitutions: It can be difficult to source key limes, so regular limes will work fine.
Make ahead: The cakes and frosting can be made up to one day ahead. Store the cakes tightly wrapped at room temperature, and the frosting in an airtight container in the refrigerator. Let the frosting come to room temperature before assembling the cake. (The cakes can be baked, cooled, well wrapped, and frozen for up to 3 months. When ready to use, thaw in the refrigerator overnight.)
Alternatively, the cake can be assembled and decorated up to one day before serving. Refrigerate uncovered and let the cake come to room temperature before serving.
Storage: The cut cake can be stored with a piece of plastic wrap pressed against the cut sides for up to one week in the refrigerator. Let come to room temperature before serving.
Stephanie Loo is a contributor to TheKitchn.com, a nationally known blog for people who love food and home cooking. Submit any comments or questions to [email protected].
