Coconut Key Lime Crumb Bars

Tangy, tropical, and utterly irresistible, these Coconut Key Lime Crumb Bars bring a taste of the Florida Keys straight to your kitchen. The perfect balance of zesty key lime filling sandwiched between buttery coconut crumb layers creates a refreshing treat that’s both indulgent and bright. Each bite delivers a delicious contrast of textures—crisp, creamy, and crumbly all at once. You’ll learn how to create these paradise-inspired bars that transport you to sunny shores with every mouthful.

Why You’ll Love This Recipe

These Coconut Key Lime Crumb Bars are about to become your new favorite dessert for so many reasons. The vibrant key lime filling packs a perfect pucker that’s balanced by the sweetness of condensed milk, creating that classic key lime pie flavor in a convenient bar form. The coconut-infused shortbread base and crumble topping add a tropical dimension that elevates these bars beyond ordinary citrus desserts.

What makes these bars truly special is their versatility—they’re elegant enough for special occasions but simple enough for everyday treats. The contrast between the buttery, coconut-flecked crumb and the silky-smooth lime filling creates an irresistible textural experience. Plus, they’re make-ahead friendly, actually improving in flavor after chilling overnight, which makes them perfect for entertaining or meal prep.

Best of all, these bars require no special equipment or techniques, just simple, straightforward steps that yield impressive results every time.

Ingredients

For the Coconut Crumb Mixture:

• 2 cups (250g) all-purpose flour
• 1 cup (200g) granulated sugar
• 1 cup (90g) sweetened shredded coconut
• 1/2 teaspoon salt
• 1 cup (226g) unsalted butter, cold and cubed
• 1 teaspoon vanilla extract

For the Key Lime Filling:

• 1 can (14 oz/396g) sweetened condensed milk
• 4 large egg yolks
• 1/2 cup (120ml) fresh Key lime juice (about 12-15 Key limes or substitute regular limes)
• 1 tablespoon Key lime zest, plus more for garnish
• 1/4 teaspoon salt

Key lime juice is the star ingredient here—authentic Key limes are smaller and more aromatic than regular Persian limes, with a distinctive tart-sweet flavor. If you can’t find Key limes, regular lime juice works well, though the flavor will be slightly different. The sweetened condensed milk not only adds creamy sweetness but also helps the filling set perfectly without baking.

Pro Tips

Properly Chill the Bars
For the cleanest slices and best flavor development, patience is key. These Coconut Key Lime Crumb Bars need at least 4 hours in the refrigerator, but overnight chilling produces the best results. The filling will set completely, and the flavors will meld beautifully. When you’re ready to slice, use a sharp knife dipped in hot water and wiped clean between cuts for professional-looking bars.

Maximize Lime Flavor
To extract the most juice from your limes, roll them firmly on the counter before cutting. This breaks down the cell walls inside the fruit, releasing more juice. For zesting, use only the green outer layer of the lime peel, avoiding the bitter white pith beneath. Adding a small amount of zest to both the filling and the crumb mixture intensifies the lime flavor throughout the bars.

Perfect Crumb Texture
For the ideal crumbly texture, keep your butter cold until the moment you use it. Cut it into small cubes and blend it into the dry ingredients using a pastry cutter or your fingertips until the mixture resembles coarse crumbs—don’t overmix to a paste. Press only the base layer firmly; the top crumble should be sprinkled loosely for that perfect contrasting texture.

Instructions

Step 1: Prepare the Baking Pan
Preheat your oven to 350°F (175°C). Line a 9×13-inch baking pan with parchment paper, leaving some overhang on the sides to easily lift the bars out later. This step is crucial for clean removal of your Coconut Key Lime Crumb Bars once they’re baked and chilled.

Step 2: Make the Coconut Crumb Mixture
In a large bowl, whisk together the flour, sugar, shredded coconut, and salt until well combined. Add the cold cubed butter and vanilla extract, then use a pastry cutter or your fingertips to work the mixture until it resembles coarse crumbs with pea-sized pieces of butter throughout. The texture should be crumbly but hold together when pressed. Set aside 1 1/2 cups of this mixture for the topping.

Step 3: Form the Base Layer
Press the remaining crumb mixture firmly into the bottom of your prepared pan, creating an even layer. Use the bottom of a measuring cup to really compact the crust, which helps it hold together when serving. Bake this base layer for 15 minutes until just beginning to turn golden at the edges.

Step 4: Prepare the Key Lime Filling
While the base is baking, whisk together the sweetened condensed milk and egg yolks in a medium bowl until smooth. Gradually add the Key lime juice, whisking constantly—you’ll notice the mixture beginning to thicken as the acid reacts with the condensed milk. Stir in the lime zest and salt until fully incorporated.

Step 5: Assemble and Bake
Pour the Key lime filling over the hot partially-baked crust, spreading it into an even layer. Sprinkle the reserved crumb mixture evenly over the top, allowing some of the filling to peek through. Return the pan to the oven and bake for 25-30 minutes, until the topping is golden brown and the filling is just set (it might still have a slight jiggle).

Step 6: Cool and Chill
Allow the bars to cool completely at room temperature (about 1-2 hours), then refrigerate for at least 4 hours or preferably overnight. The chilling step is essential for developing flavor and achieving the perfect texture in your Coconut Key Lime Crumb Bars.

Variations

Tropical Fruit Twist
Transform these Coconut Key Lime Crumb Bars into an even more tropical treat by adding 1/2 cup of finely diced dried mango or pineapple to the crumb mixture. For an extra layer of flavor, replace 1/4 cup of the lime juice with passion fruit juice or puree. This variation intensifies the vacation vibes and creates a complex fruit flavor that’s absolutely stunning.

Coconut Lime Cheesecake Bars
For a creamier, richer version, add 8 ounces of softened cream cheese to the filling mixture. Beat the cream cheese until smooth before adding the condensed milk and proceeding with the recipe as directed. The result is a hybrid between cheesecake and key lime pie with all the tropical coconut notes, creating an even more indulgent dessert that’s perfect for special occasions.

Gluten-Free Option
These bars are easily adaptable for gluten-free diets by substituting the all-purpose flour with a high-quality gluten-free flour blend that contains xanthan gum. The coconut in the crumb mixture helps maintain a delicious texture even without traditional wheat flour, making these treats accessible to more people without sacrificing flavor or texture.

Storage and Serving

These Coconut Key Lime Crumb Bars will keep beautifully in an airtight container in the refrigerator for up to 5 days, actually improving in flavor after the first day as the coconut and lime notes continue to meld. For longer storage, you can freeze the bars for up to 3 months—simply wrap individual portions in plastic wrap, then aluminum foil, and place in a freezer bag. Thaw overnight in the refrigerator before serving.

For an elegant dessert presentation, serve each bar on a small plate with a dollop of fresh whipped cream and a tiny wedge of lime. Add a light dusting of toasted coconut over the top for extra visual appeal and texture.

These bars are also perfect for picnics or potlucks—just keep them chilled in a cooler until ready to serve. For a delightful twist, try serving them slightly frozen on hot summer days; they become almost ice cream bar-like in texture while still maintaining their vibrant flavor.

FAQs

Can I use regular limes instead of Key limes?
Yes, you can substitute regular Persian limes if Key limes aren’t available. You’ll need about 4-5 regular limes to get 1/2 cup of juice. The flavor will be slightly less aromatic and a bit more tart, but still delicious.

Why didn’t my filling set properly?
The filling for Coconut Key Lime Crumb Bars sets through a chemical reaction between the acidic lime juice and the proteins in the condensed milk and egg yolks. Ensure you’re using the full amount of lime juice and that your condensed milk hasn’t expired. Also, make sure the bars are completely chilled before slicing.

Can I make these bars ahead of time?
Absolutely! These bars actually taste better after chilling overnight, making them perfect for make-ahead desserts. They keep well in the refrigerator for up to 5 days.

Is there a dairy-free version of this recipe?
You can make a dairy-free version by using coconut oil instead of butter in the crumb mixture and dairy-free condensed milk (usually coconut-based) for the filling. The coconut flavor will be more pronounced, but still delicious.

Can I add other citrus flavors to these bars?
Yes! Try a mixture of lime and lemon juice, or even add a splash of orange juice for a different citrus profile. Just maintain the same total amount of juice (1/2 cup) to ensure proper setting.

Conclusion

These Coconut Key Lime Crumb Bars are tropical indulgence at its finest — a perfect balance of tangy citrus, creamy filling, and buttery coconut crumble that transports you straight to a beachside café. They’re the kind of dessert that bridges seasons, bringing brightness to winter days and refreshing relief during summer heat. Whether you’re hosting a gathering, contributing to a potluck, or simply treating yourself to something special, these bars deliver a slice of paradise that keeps everyone coming back for more.

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