Lime and Coconut Layer Cake has three layers of white cake flavored with lime zest and key lime flavoring, filled with lime curd and frosted with coconut rum Swiss meringue buttercream.
Lime Layer Cake Ingredients
- Whole milk: The fat in whole milk helps to tenderize the cakes crumb. It also interacts with the flour to create just enough gluten to form the cakes structure.
- Egg whites: helps create structure.
- Key lime flavoring: helps with flavor.
- Cake flour: has a lower protein content than all-purpose flour which helps create a delicate crumb.
- Granulated sugar: Sugar not only sweetens the cake but it also helps tenderize, leavens and browns.
- Baking powder: is a leavener that contains baking soda and cornstarch. Baking soda reacts twice. The first is when it comes into contact with liquid and then when it is heated. Baking soda can’t be used as a substitute for baking powder.
- Salt: helps bring out the sweetness in the cake.
- Fresh lime zest: helps with flavor.
- Unsalted butter: tenderizes, moistens, leavens, browns, and flavors.
I used the same recipe for my lime curd that I use in my spring Lemon Layer Cake. Simply substitute the lemons for limes.
Coconut Swiss Meringue Buttercream Tips
- Make sure your mixer bowl is clean.
- Be sure to whisk together the egg whites and sugar well or the eggs could start to cook on their own.
- Your double boiler should stay at a simmer the entire time.
- Use room temperature butter.
- Add butter in one tablespoon at a time.
Cake Crumb Coating
A crumb coat is a thin layer of buttercream that holds loose crumbs and seals in the cake. Crumb coating a cake gives you a perfect base to start cake decorating on.
How To Crumb Coat A Cake
To crumb coat, add a thin layer of buttercream on the top and sides of the cake using a small offset cake spatula. Be sure not to mix in the crumb coating buttercream with your clean buttercream. Once your cake has been crumb coated chill in the refrigerator for 15 to 30 minutes.
- Lime Cake: lime zest and key lime flavoring help flavor the fluffy white cake layers.
- Lime Curd: freshly squeezed lime juice and lime zest flavor this homemade lime curd.
- Coconut Swiss Meringue Buttercream: coconut rum and coconut emulsion flavor this luscious buttercream.
Lime and Coconut Layer Cake Baking Schedule
- Day 1: Prepare lime cake layers and lime curd.
- Day 2: Prepare coconut Swiss meringue buttercream, assemble and serve.
I recommend using gel food colors. The liquid food colors will change the consistency of your buttercream and you’ll have to add a lot of liquid to your buttercream to get the color you’re looking for. Gel colors are more intense and won’t change the consistency of your buttercream and you don’t usually have to use a lot.
For my Lime and Coconut Layer Cake I used Americolor Mojito gel food coloring.
Two Toned Buttercream
- Start with a chilled and crumb coated cake.
- Divide buttercream and color one with Americolor gel food coloring Mojito.
- Place a dollop of uncolored buttercream on the top of the cake and spread out in an even layer.
- Fit 2 piping bags with a round piping tip or a plain round coupler.
- Fill one bag with uncolored buttercream.
- Fill the other piping bag with green buttercream.
- Starting on the bottom of the cake, with the green buttercream, pipe a ring of buttercream around the cake. Do this around 3 to 4 times until the piping is about halfway up the cake.
- Use the uncolored buttercream and finish with rings moving up to the top of the cake.
- Line an 8-inch round acrylic disc with parchment paper and gently press on the top of the cake (paper side down). Making sure to line up the disc with the cake board.
- Use a cake scraper by gently pressing it against the bottom cake board and top acrylic disk and rotate the cake turntable to even out the buttercream. Fill in any gaps and continue to use the cake scraper and turntable until smooth.
Cake Decorating Tools
- 8-inch round cake board
- Cake turntable
- Piping bags (3)
- Round piping tips or couplers (2)
- Small offset cake spatula
- 8-inch round acrylic cake disc
- Cake scraper
- Wilton Piping Tip #1M
- 3 8-round cake pans
- Nonstick baking spray
- Stand mixer
- 8-inch round cake board
- Cake turntable
- Piping bags (3)
- Round piping tip or coupler (2)
- Small offset spatula
- 8-inch round acrylic disc
- Cake scraper
- Wilton piping tip #12
- Lime slices (garnish)
- Coconut flakes (garnish)
- 1 cup (8 ounces) whole milk, at room temperature
- 6 large egg whites, at room temperature
- 1 1/2 teaspoons lime flavoring
- 2 1/4 cups (9 ounces) cake flour
- 1 3/4 cup (12 1/4 ounces) granulated sugar
- 4 teaspoons baking powder
- 1 teaspoon salt
- 1 tablespoon fresh lime zest
- 12 tablespoons unsalted butter, cut into tablespoon sized pieces, at room temperature
LIME CURD FILLING
- 3 whole eggs
- 3/4 cup (5.25 ounces) granulated sugar
- Pinch of salt
- 1/2 cup freshly squeezed lime juice
- 1 tablespoon lime zest
- 4 tablespoons unsalted butter, cut into tablespoon sized pieces
COCONUT RUM SWISS MERINGUE BUTTERCREAM
- 1/2 cup plus 2 tablespoons egg whites
- 1 1/4 cups (8.75 ounces) granulated sugar
- 2 cups (4 sticks) unsalted butter, cut into tablespoon sized pieces, at room temperature
- 2 teaspoons vanilla extract
- 2 tablespoons coconut rum
- 1 teaspoon coconut emulsion
- Adjust an oven rack to the center position and heat oven to 350 degrees. Spray 3 8-inch round cake pans with nonstick baking spray and set aside.
- In a bowl or a 4 cup liquid measuring cup, whisk together milk, egg whites and lime flavoring. In the bowl of a stand mixer, with the paddle attachment attached, mix the flour, sugar, baking powder, salt and lime zest on low speed until combined. Add butter one tablespoon at a time until the mixture forms pea-sized pieces, about 1 minute. Reserve ½ cup of the milk mixture and pour the remaining to the flour mixture and mix on medium-high speed until light and fluffy, about 1 minute. Reduce the mixer speed to medium-low and add the reserved ½ cup milk mixture to the batter and mix until combined, about 30 seconds. Do not over mix. The batter may look curdled. Give the batter a final stir by hand with a rubber spatula.
- Divide the batter evenly between the prepared cake pans and smooth tops with a rubber spatula. Gently tap cake pans on the counter to settle the batter and bake until a toothpick inserted in the centers comes out with a few moist crumbs attached, about 20 to 25 minutes, switching and rotating pans halfway through baking.
- Let cakes cook in their pans on wire racks for 10 minutes. Invert cakes on to wire racks to cool completely, about 2 hours.
- In a medium sized saucepan, whisk together the eggs, sugar, salt, lime juice and zest.
- Over low heat, whisk constantly for about 15 to 20 minutes or until the mixture starts to thicken. The curd should coat the back of a wooden spoon without being translucent.
- Remove the curd from the heat and stir in the butter. Strain the curd through a fine-mesh sieve into a bowl to remove any solids that may have formed while cooking. Place a piece of plastic wrap on the surface of the curd and chill in the refrigerator for at least 3 hours or overnight.
COCONUT RUM SWISS MERINGUE BUTTERCREAM
- In the bowl of a stand mixer fitted with the whisk attachment, pour in the egg whites and sugar and whisk by hand until combined. Fill a medium saucepan with about 2 inches of water and bring to a simmer. Place mixer bowl on top, being sure the bottom of the bowl does not touch the water and attach a candy thermometer.
- Whisking occasionally, heat the egg mixture until the temperature reaches 160 degrees. Once the mixture reaches 160 degrees, transfer to a stand mixer and beat the mixture on high speed for 10 minutes or until medium-stiff peaks form. At this point the outside of the mixer bowl should be room temperature. Switch out the whisk attachment with the paddle attachment and with the mixer on low speed, add the butter one tablespoon at a time, and then add the vanilla extract, rum and coconut emulsion. Once combined, turn the mixer speed to medium-high and beat until buttercream is smooth, about 4 minutes. Reduce the mixer speed to low and beat for 1 more minute to remove as many air bubbles from the buttercream as possible.
- Place an 8-inch round cake board on a cake turntable and center the first layer of cake on the cake board. Fit a piping bag with a round piping tip or coupler and fill with about 1 1/2 cups buttercream. Pipe a buttercream dam around the edge of the cake. Spread half of the lime curd in the center and using a small offset spatula, spread out in an even layer until the filling reaches the buttercream dam.
- Place the second cake layer on top and gently press down to adhere. Pipe a buttercream dam around the edge of the cake and place the remaining lime curd on the center of the cake and spread out in an even layer with your offset spatula.
- Place the last cake layer on top (bottom side up). Add about 1 cup of buttercream spread a thin layer of buttercream over the entire cake creating a crumb coat. Chill the crumb coated cake in the refrigerator for 30 minutes.
- If you’re using an acrylic disc, line one side with parchment paper using a small amount of buttercream to attach it. Apply a large amount of buttercream on the top of the cake and spread out evenly to the edge of the cake. You should have access buttercream hanging off the edge of the cake. Gently press the acrylic disc down on top. Make sure the disc and the bottom cake board line up and that the top of the cake is level.
- Fit a piping bag with a round piping tip or coupler and fill with green tinted buttercream. Starting from the bottom of the cake, pipe buttercream around the bottom edge. Do this about three or for times around. The green buttercream should come up about halfway from the cake. Fit another piping bag with another round piping tip or coupler and fill with uncolored buttercream. Pipe buttercream around the cake starting from the green buttercream and working all the way up cover the entire side of the cake.
- Gently press the cake scraper on the bottom cake board and the top acrylic disc and rotate the turntable to smooth out the buttercream. You may need to do this 2 to 3 times. Be sure to clean your cake scraper with every rotation. Fill in any gaps in with the appropriate color buttercream and smooth over again. Chill the cake in the refrigerator for 30 minutes.
- With an offset cake spatula, gently remove the acrylic disc and fill in any spaces on the top with more buttercream and carefully smooth the top of the cake and edges, cleaning the cake spatula with every swipe.
- Fit a piping bag with Wilton piping tip 1M and fill with both colors of remaining buttercream. Pipe some swirls around the edge of the cake. Place lime slices between each swirl and fill the center with coconut flakes and serve.
Cake layers can be stored wrapped in plastic in an airtight container in the refrigerator for up to 3 days.
Lime curd can be made up to 1 week in advance, stored in an airtight container in the refrigerator.
Assembled cake can be stored in an airtight container in the refrigerator for up to 3 days. Bring to room temperature before serving.
Nutrition Information:Yield: 12 Serving Size: 1
Amount Per Serving: Calories: 566Total Fat: 32gSaturated Fat: 15gTrans Fat: 0gUnsaturated Fat: 15gCholesterol: 140mgSodium: 613mgCarbohydrates: 61gFiber: 2gSugar: 32gProtein: 9g
*Nutrition information is an estimate and will vary.*