Key Lime Cloud Entremets
Bikini Bottom-inspired key lime mousse cakes, based on the underwater city from SpongeBob SquarePants.
The Krusty Krab may have perfected the burger, but I have questions about the dessert menu.
For this recipe, I imagined what might happen if Bikini Bottom, SpongeBob’s fictional underwater city, had its own tiny pastry case. The answer: Key Lime Cloud Entremets with key lime cheesecake mousse, a tart key lime crémeux center, and salty brown butter coconut-graham croustillant.
They’re tropical, creamy, citrusy, crunchy, and dressed up with seafoam colors, bubbly droplets, coral, and tiny starfish cookies. Not a literal character dessert, but definitely a little pastry that feels like it knows where the jellyfish fields are.
What are Key Lime Cloud Entremets?
These are individual frozen mousse cakes made with three main components: a key lime cheesecake mousse, a frozen key lime crémeux insert, and a crisp coconut-graham croustillant base. They’re assembled in silicone cloud molds, frozen solid, unmolded, and finished with velvet spray and playful undersea decorations.
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Recipe Overview
Yield: 6 cloud entremets, with a small production buffer
Mold: 7.5 cm puffy cloud silicone molds
Finished dessert: Key lime cheesecake mousse, key lime crémeux insert, and salty brown butter coconut-graham croustillant base
Components
Key lime crémeux inserts
Salty brown butter coconut-graham croustillant bases
Key lime cheesecake mousse
Velvet spray
Optional decorations: white chocolate coral, glaze droplets, and starfish cookies
Equipment You’ll Need
Small insert molds / small sheet pan + cookie cutters
Digital scale
Thermometer
Immersion blender
Small food processor
Stand mixer or hand mixer
Rolling guides or dowels
Parchment paper
Sharp cutter for the croustillant bases
Make-Ahead Note
This recipe is best made over 2 to 3 days. The crémeux inserts need to freeze solid before assembly, and the finished entremets need to freeze completely before unmolding and decorating.
Suggested Production Schedule
Day 1
Make the key lime crémeux inserts and freeze overnight.
Day 2
Make the coconut-graham croustillant bases.
Make the key lime mousse.
Assemble the entremets and freeze until solid.
Day 3, or later
Unmold, velvet spray, decorate, thaw, and serve.
Component 1: Key Lime Crémeux Inserts
A tart, creamy key lime center that gives the entremets a brighter citrus bite.
Ingredients
2.35 g powdered gelatin
14 g cold water
70 g key lime juice, divided
3.5 g fresh lime zest, very finely microplaned
52 g granulated sugar
60 g sweetened condensed milk
55 g egg yolks
35 g whole egg
50 g white chocolate
45 g unsalted butter, softened but cool
1.5 g fine sea salt
2 g vanilla extract or paste
0.3–0.5 g citric acid, optional
Tiny amount yellow-lime gel color, optional
Method
Sprinkle the gelatin over the cold water and let bloom for 5–10 minutes, until fully hydrated.
Combine the lime zest and sugar in a small food processor. Pulse until fragrant and damp.
In a saucepan, combine the lime-sugar mixture, sweetened condensed milk, egg yolks, whole egg, salt, and 45–50 g of the key lime juice.
Cook over low to medium-low heat, stirring constantly, until the mixture reaches 82–84°C / 180–183°F. Do not boil.
Strain the hot mixture over the white chocolate. Let sit for 1 minute, then add the bloomed gelatin. Blend with an immersion blender until smooth and glossy.
When the mixture cools to 40–45°C / 104–113°F, blend in the butter, vanilla, remaining key lime juice, optional citric acid, and optional gel color.
Shape the crémeux inserts using either insert molds or the sheet-pan method.
For insert molds: Pipe about 22–26 g crémeux into each mold. Tap gently to remove air bubbles.
For the sheet-pan method: Line a small sheet pan or shallow tray with plastic wrap, smoothing it as much as possible. Pour in the crémeux and spread into an even layer, about the desired thickness for your inserts.
Freeze overnight, or until completely solid.
If using the sheet-pan method, lift the frozen crémeux slab from the tray and cut out insert shapes with a cookie cutter. Work quickly while the crémeux is frozen firm, then return the cut inserts to the freezer.
Before assembly, place the frozen inserts back in the freezer uncovered for 20–30 minutes. This helps slightly dry the exterior so they are easier to handle.
Crémeux Notes
Do not let the custard boil. Gentle cooking keeps the texture smooth and silky.
The lime juice is added in two stages to keep the finished crémeux bright and fresh-tasting after freezing.
If using the sheet-pan method, make sure the crémeux is frozen completely solid before cutting.
Work quickly when cutting frozen crémeux. If it begins to soften, return it to the freezer before continuing.
The inserts must be frozen solid before assembly.
Component 2: Salty Brown Butter Coconut-Graham Croustillant
A crisp, sandy, salty base with toasted coconut, graham cracker, brown butter, white chocolate, and feuilletine.
Ingredients
145 g graham cracker crumbs, fine but not powdered
40 g toasted coconut, finely chopped
48 g feuilletine
28 g light brown sugar
4.5 g fine sea salt
80 g browned unsalted butter, including toasted milk solids
135 g white chocolate
28 g cocoa butter
8 g neutral oil
6–8 g toasted macadamia, finely crushed, optional
Method
Brown the butter until deeply golden, nutty, and fragrant. Reweigh and use 80 g browned butter, including the toasted milk solids.
Combine the graham cracker crumbs, toasted coconut, brown sugar, and salt with the warm browned butter.
Spread the mixture onto a parchment-lined tray and bake at 325°F / 165°C for 8–10 minutes, stirring once halfway through. Cool completely.
Fold in the feuilletine and optional toasted macadamia. Do not crush the feuilletine too finely.
Melt the white chocolate, cocoa butter, and neutral oil together until smooth.
Pour the melted mixture over the crumb mixture and fold until evenly coated.
Press firmly between two sheets of parchment and roll to 5–6 mm thick.
Refrigerate for 20 minutes, then lightly compress again with a rolling pin to improve cohesion.
Chill until firm but not fully hard. Cut bases slightly larger than the cloud mold footprint.
Chill or freeze flat until solid. Store airtight with parchment between layers.
Croustillant Notes
Use fine graham cracker crumbs, but not powder. A little texture helps the base stay sandy and crisp.
Do not over-crush the feuilletine. It should keep some delicate crispy shards.
The 20-minute chill and second compression help the slab hold together and cut more cleanly.
Chill the croustillant before cutting, but do not let it become so hard that it shatters.
The salt level is intentional. Cold desserts mute flavor, and the salt helps the key lime taste brighter.
Component 3: Key Lime Cloud Mousse
A soft key lime cheesecake mousse designed for clean unmolding and velvet spraying.
Ingredients
180 g full-fat cream cheese, room temperature
150 g sweetened condensed milk
52 g key lime juice
3.5 g fresh lime zest, very finely microplaned
12 g granulated sugar
55 g white chocolate
240 g heavy cream, divided
50 g for heating
190 g for whipping
5.3 g powdered gelatin
31 g cold water
1.7 g fine sea salt
2 g vanilla extract or paste
Tiny amount spirulina or teal oil-dispersible color, optional
Method
Sprinkle the gelatin over the cold water and let bloom for 5–10 minutes, until fully hydrated.
Combine the lime zest and sugar in a small food processor. Pulse until fragrant and damp.
Heat 50 g heavy cream until steaming but not boiling. Whisk in the bloomed gelatin until dissolved.
Pour the hot cream-gelatin mixture over the white chocolate. Let sit for 1 minute, then whisk until smooth. Cool to 35–40°C / 95–104°F.
Paddle the cream cheese until completely smooth, scraping the bowl as needed.
Add the sweetened condensed milk, lime-sugar mixture, salt, and vanilla. Mix until glossy and smooth.
With the mixer on low speed, gradually stream in the key lime juice.
Slowly stream in the warm white chocolate-gelatin mixture. Scrape thoroughly and mix until silky.
Whip the remaining 190 g heavy cream to soft peaks. Do not overwhip.
Fold one-third of the whipped cream into the mousse base to lighten it. Fold in the remaining cream in two additions.
Use immediately for assembly.
Mousse Notes
Use fully room-temperature cream cheese. Cold cream cheese can leave small lumps in the mousse.
Whip the cream only to soft peaks. Stiff cream can make the mousse denser instead of cloudlike.
Cool the white chocolate-gelatin mixture before adding it to the cheesecake base so the mousse stays smooth.
Use the mousse immediately after folding in the whipped cream.
Component 4: Velvet Spray Finish
Velvet spray gives the frozen entremets their soft, seafoam-like finish. I use a simple mixture of approximately equal parts melted white chocolate and melted cocoa butter, sprayed through a basic airbrush. No tempering is needed.
For this design, I used two colors and sprayed each generously to create a softly beaded, velvet-like texture.
Ingredients
Velvet spray mixture:
50 g white chocolate
50 g cocoa butter
Oil-dispersible food coloring, as needed
This makes enough velvet spray mixture for a generous coating on 6 small entremets.
For this design, divide the mixture into two portions and tint each portion a different seafoam-inspired color.
Method
Melt the white chocolate and cocoa butter together until completely smooth and fluid, with no unmelted bits or lumps.
Divide the mixture into separate portions if using more than one color.
Add oil-dispersible coloring to each portion, if using. Stir or blend until fully incorporated and completely smooth.
Unmold the entremets while completely frozen.
Spray the frozen entremets with the first color, keeping the airbrush moving so the coating builds evenly. Additional passes will build the texture up more.
Spray with the second color while the entremets are still frozen, layering the colors until you have a soft, beaded velvet texture.
Transfer the sprayed entremets to the refrigerator to fully set before decorating.
Velvet Spray Notes
The entremets must be frozen solid before spraying. The velvet texture forms when the warm cocoa butter-chocolate mixture hits the frozen surface.
Make sure the mixture is fully melted and lump-free before adding it to the airbrush. Any unmelted bits can clog the nozzle.
Keep the spray mixture warm and fluid while working. If it starts to thicken, gently rewarm it.
Use oil-dispersible colors only. Water-based colors can cause the chocolate mixture to seize.
Spray inside a box or protected area, because cocoa butter mist likes to coat everything.
Assembly & Finishing Notes
Press the frozen crémeux insert gently into the mousse so it sits centered.
Pipe mousse around the insert to avoid air pockets.
Freeze the entremets until completely solid before unmolding.
Velvet spray the entremets while they are still frozen.
Place the velvet-sprayed entremet onto the croustillant base and store refrigerated until serving – the mousse will soften and adhere to the base. If serving immediately, you can secure the entremets to the croustillants with a small amount of melted white chocolate or cocoa butter.
Storage and Serving
Store finished entremets in the refrigerator after thawing. For the best texture, enjoy within 1–2 days.
For the best texture and flavor, let the entremets sit at room temperature for 10–15 minutes before serving.
The mousse should be soft and creamy, the crémeux should be silky, and the croustillant should remain crisp but sliceable.
Final Thoughts
Somewhere between key lime pie and a Krusty Krab dessert menu, these little clouds floated into existence.
This is the first recipe in my Cartoon Worlds, But Make It Dessert series, where I turn familiar animated worlds into original pastry designs through flavor, texture, color, and edible storytelling. Follow along on Instagram, TikTok, YouTube, and Facebook at @inspiredtotaste for more tiny pastry worlds.