Key Lime Baked Alaska Recipe

Combine key lime juice, light rum, coconut water, simple syrup, lime zest and sea salt in a mixing bowl and whisk until sugar is dissolved. Chill mixture in refrigerator for 30 minutes so flavors marry.

Pour chilled mixture into an ice cream machine and churn according to manufacturer instructions until it reaches a soft-sorbet consistency, about 20–30 minutes. If you don't have an ice cream maker, pour into a shallow metal pan, freeze for 45 minutes, then scrape with a fork to break up ice crystals and repeat every 30–45 minutes until smooth (about 3–4 cycles).

Line an 8–9 inch dome mold or a large ovenproof mixing bowl with plastic wrap or parchment. Spoon or press chilled sorbet into the mold, forming a dome that will be the interior of the Baked Alaska. Smooth surface, cover with plastic wrap, and freeze until firm, at least 4 hours or overnight.

Set a small bowl over a larger bowl of ice water and have it ready for cooling the curd.

In a medium saucepan, whisk together key lime juice, sugar, egg yolks and the whole egg until smooth and homogenous.

Place the saucepan over low–medium heat and cook the mixture, stirring constantly with a silicone spatula, scraping the bottom, until it thickens enough to coat the spatula and registers 170–175°F (77–79°C) on an instant-read thermometer, about 6–8 minutes. Do not boil.

Remove from heat and immediately whisk in cold cubed butter a few pieces at a time until fully incorporated and the curd is glossy. Stir in lime zest and a pinch of salt.

Transfer curd to the prepared chilled bowl over ice and stir occasionally until it cools to room temperature to stop cooking. When cooled, spread a 1/2-inch layer of curd in the center of the frozen sorbet dome (you can unmold the sorbet dome briefly onto a parchment-lined tray, spread curd, then re-cover with sorbet if desired). Return assembled dome to the freezer until curd is fully set, about 1 hour.

Preheat oven to 350°F (175°C). Line an 8-inch round cake pan or baking sheet with parchment and grease lightly.

In a large bowl, whisk together eggs and granulated sugar until light and thick, about 3–5 minutes by electric mixer on medium-high until ribbon stage (when a trail of batter rests on the surface briefly).

Fold in vanilla extract, salt, then sifted flour in two additions, folding gently with a spatula to keep as much air as possible. Finally fold in melted butter in a thin stream until incorporated.

Spread the batter into the prepared pan to make a thin disc about 1/2 inch thick. Bake 10–12 minutes or until the top is pale golden and springs back lightly. Remove from oven and dust with 1 tsp sugar; cool briefly then invert and trim to an 8-inch round if needed.

When cooled, place the sponge cake disc on a freezer-safe tray and freeze for 30 minutes so it's firm enough to support the sorbet dome.

Unmold the sorbet dome from its mold onto the frozen sponge cake disc (or place sponge on serving plate and set dome on top). If you applied curd to the sorbet earlier, ensure it remains cold and centered. Press gently so dome adheres to cake. Return the entire assembly to the freezer until extremely firm, at least 2 hours (overnight preferred).

Prepare an ice bath in a medium bowl (ice + a little water). Combine egg whites and sugar in a heatproof bowl (bowl should fit over a saucepan without touching the water). Add cream of tartar.

Place the bowl over a saucepan of gently simmering water (double boiler). Whisk constantly until sugar dissolves and the mixture reaches 160–165°F (71–74°C) and feels smooth between your fingers (no graininess), about 4–6 minutes.

Remove the bowl from heat and immediately transfer the whites and sugar to a stand mixer fitted with a whisk or use an electric hand mixer. Whisk on high until stiff glossy peaks form and the bowl has cooled to near room temperature, about 6–8 minutes. Add vanilla in the last 30 seconds.

Working quickly, remove the frozen Baked Alaska from the freezer and place on a heatproof serving platter. Starting at the bottom edge, spread or pipe the Swiss meringue all over the dome and sides in a 1–1.5 inch layer, sealing the cake and sorbet completely (no gaps). Create peaks with the spatula for an attractive surface.

If you like toasted coconut, sprinkle the shredded unsweetened coconut on the meringue at the base or lightly on top where desired (optional).

Using a kitchen torch, carefully toast the meringue evenly, moving the flame in circular motions until golden brown peaks appear, about 1–3 minutes depending on torch intensity. Hold torch 2–4 inches away; avoid prolonged heat on one spot to prevent melting the sorbet core. Serve immediately, slicing with a hot dry knife (dip in hot water and dry between cuts) to get clean slices.