Key Lime Cake

Weigh out the ingredients


You'll need cake flour, butter, whole milk, sugar, eggs, oil, key limes, vanilla extract, baking powder, and salt.

Mix sugar & zest


In the bowl of a stand mixer fitted with a paddle attachment, add the sugar and key lime zest. Rub them together with your fingers until it resembles wet sand and smells aromatic.

To the sugar, mix in the flour, baking powder, and salt. Cut up 5 ½ tablespoons of butter into small cubes and add to the flour mixture. Mix on low speed until it resembles wet sand.

Add dry ingredients & butter


Add the oil, whole milk, and vanilla, and mix until just combined.

Add wet ingredients


In a separate medium bowl, add the egg whites. Use an electric hand mixer to whip them until medium peaks form.

Whip egg whites


Gently fold the whipped egg whites into the batter with a rubber spatula until just combined.

Fold in egg whites


Divide the cake batter between the prepared pans.

Divide batter


Bake for about 22-25 minutes or until the cakes start to pull away from the sides of the pans. Immediately turn the cakes out onto a wire rack to cool completely. Once cool, wrap the cakes in plastic wrap and freeze until ready to decorate.

Bake, chill, & freeze


Whisk egg yolks and dry ingredients, then mix in the fresh lime juice. Melt butter on stovetop, then pour in egg yolk mixture, then turn to medium heat and mix constantly for 3-4 minutes. Remove from heat, strain curd into a jar and chill for at least 1 hour or overnight.

Make the key lime curd


Whisk egg whites, sugar, and salt until combined. Place over double boiler and whisk until 160 degrees F. Remove from heat, whisk on medium-high speed until medium peaks form. Add  vanilla and whisk to stiff peaks. Whisk on ow speed until cooled to at least 85ºF.

Make swiss meringue


Add cubed butter to meringue a few pieces at a time, allowing them to fully incorporate before adding more. Keep beating for a few more minutes to come together. Change the whisk attachment to the paddle and keep mixing on low speed until smooth.

Add butter


Place the first cake layer on a cake stand. Pipe a dam of buttercream around the edge of the cake. Fill the center with an even layer of key lime curd. Top with the second cake layer and repeat.

Assemble cake


Add the last cake layer and top with a few scoops of buttercream. Use an offset spatula to smooth out the top, and spread the excess all over the sides. Continue decorating the cake as desired. Top with key lime zest, and enjoy!