Key Lime Cake From Isabel Coss

January 21, 2022
3 Ratings
Photo by Rocky Luten, prop styling by Molly Fitzsimons, food styling by Ericka Martins
  • Prep time 30 minutes
  • Cook time 1 hour
  • Serves 12
Author Notes

This eucalyptus key lime cake recipe is one of the first desserts that I learned to make. I love tres leches cake just as much, so this recipe is a combination, a hybrid of those two desserts. This cake is also a variation of a recipe in Mexico called Carlota, a cake which is equal amounts of condensed milk to lime juice so it curdles together. It's layered with sponge cake, then frozen and sliced. Making Carlota is how I fell in love with pastries.

I know some people are afraid of using white chocolate, but in my experience, it's just a matter of the brand of white chocolate you use. When you have a good-quality white chocolate, your baked goods will taste delicious. It has that cocoa butter flavor that reminds me of condensed milk—without actually having to use condensed milk.

You shouldn't eat eucalyptus raw, but in this case, it's safe to use a few sprigs in a water bath. I wanted to create a cheesecake that tastes like eucalyptus, so I simply steamed some—it will infuse the cake while it's baking. And the best part of all is that your entire kitchen will smell like eucalyptus. —Food52

Test Kitchen Notes

Heads up: Eucalyptus contains eucalyptol, also known as cineole, which is an organic compound that's toxic in high doses. Eucalyptus leaves themselves aren't safe to eat. —The Editors

What You'll Need
Watch This Recipe
Key Lime Cake From Isabel Coss
  • Cake:
  • Cooking spray
  • All-purpose flour (for the pan)
  • 75 grams unsalted butter (about 6 tablespoons)
  • 75 grams granulated sugar (about ⅓ cup), divided
  • 200 grams white chocolate discs/wafers
  • 5 large egg yolks
  • 75 grams cream cheese (about ⅓ cup), room temperature
  • Finely grated zest of 2 limes
  • 5 egg whites
  • 75 grams fresh lime juice (about a scant ⅓ cup)
  • 30 grams all-purpose or gluten-free flour (about ¼ cup)
  • 4 sprigs eucalyptus
  • Swiss Meringue & Assembly:
  • 185 grams granulated sugar (about a heaping ¾ cup)
  • 120 grams egg whites (from about 3 large eggs)
  • Lime wedge, for the bowl (optional)
  • Juice of ½ lime
  • Finely grated lime zest, for garnish
  1. Cake:
  2. Heat the oven to 350°F. Grease a 12-cup Bundt pan with cooking spray, then coat with the flour, shaking the pan to distribute and tapping out any excess. If you want extra assurance, line the pan with a ring of parchment paper.
  3. In a double-boiler over low heat, gently melt the chocolate and butter, stirring occasionally, for about 10 minutes, until smooth (reserve the hot water for baking). Transfer the chocolate mixture to a large bowl.
  4. In the large bowl of a stand mixer fitted with the whisk attachment, whip the egg yolks, 50 grams of the sugar, the cream cheese, and lime zest, scraping down the bowl, for 5 to 7 minutes, until the ribbon stage is reached. Transfer to a small bowl.
  5. Wipe out the stand mixer bowl and pour in the egg whites. Mix on medium-low speed until foamy and bubbles form. With the motor running, gradually add the remaining 25 grams of the sugar and continue to mix for about 5 minutes, until soft peaks form.
  6. Add the lime juice to the chocolate mixture and stir to combine. Fold the egg yolk mixture into the chocolate mixture. Alternately fold the flour and egg white mixture into the chocolate mixture, beginning and ending with the flour.
  7. Pour the batter into the prepared pan. Place the Bundt pan in a large, deep pan. Arrange the eucalyptus in the large pan around the Bundt pan. Pour the reserved hot water from the double-boiler into the large pan with the eucalyptus, adding more if needed, until it reaches about halfway up the sides of the Bundt pan. Bake for 40 to 50 minutes, until a tester inserted into the thickest part comes out clean. Let cool, then refrigerate for at least 1 hour and up to 3, until cold.
  1. Swiss Meringue & Assembly:
  2. In the double-boiler, thoroughly whisk the sugar and egg whites until the sugar is dissolved, the egg whites are warm but not hot, and an instant-read thermometer registers 110°F.
  3. Run a lime wedge around the inside of the bowl of the stand mixer to get rid of any excess fat in the bowl (or just wipe out the bowl). Transfer the egg white mixture to the stand mixer bowl. Whip with the whisk attachment for 5 to 7 minutes, until glossy, pale, and fluffy. Add the lime juice and continue to whip for a few seconds, just until incorporated.
  4. Invert the cake onto a platter, warming the pan with a kitchen torch if needed. If the cake doesn’t come out seamlessly, don’t worry; you can fix any imperfections with the meringue. Scoop the meringue into a piping bag. Snip off the corner of the bag and decorate as desired. Heat the meringue with the torch to brown, if desired. Garnish with the lime zest.

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1 Review

Carolyn C. April 17, 2023
This cake looks luscious! My husband loves key lime pie, I prefer lemon. So I may switch out the lime for lemon for Mother's Day, and make with Lime for Father's Day. I need a much moister cake and this looks perfect. Thanks for sharing.