Key Lime Cupcakes

Bright, zesty, and bursting with tropical flavor, Key Lime Cupcakes are a fun and refreshing twist on classic cupcakes. They’re light, fluffy, and perfectly tart—with a creamy frosting that balances the tang just right. Whether you’re making them for a summer party, a birthday, or just because you’re craving something citrusy, these cupcakes deliver a burst of sunshine in every bite.

What sets these apart is that unmistakable key lime flavor. It’s more aromatic and slightly sweeter than regular lime, and it adds a unique zing that makes these cupcakes stand out. You don’t need to be a seasoned baker to pull this off either. With just a few basic ingredients and a little zesting and juicing, you’re on your way to one seriously impressive dessert.

I first made these on a whim during a warm afternoon when I had a bag of key limes sitting on the counter. They turned out so good that I made another batch the next day—no shame. The cupcake base is moist and tender with the subtle sharpness of lime in every bite, and the frosting? Oh, the frosting. It’s rich and creamy with a citrus punch that makes you want to lick the spoon (and the bowl, too).

These are the kind of cupcakes that get people asking for the recipe. They’re eye-catching with their pale green hue and a sprinkle of lime zest on top, and even more memorable when you taste them. If you love desserts that are both sweet and tangy, these key lime cupcakes will hit the spot every single time.

Why You’ll Love It

• Bright and Zesty Flavor: These cupcakes are packed with fresh key lime juice and zest, giving them a vibrant citrus kick that’s refreshing and not overly sweet.
• Soft, Moist Texture: The cupcake base is tender and fluffy, thanks to the perfect balance of wet and dry ingredients. Each bite practically melts in your mouth.
• Creamy Lime Frosting: The frosting is rich and velvety with just the right amount of tanginess to complement the cupcakes. It’s the kind of topping you’ll want to eat by the spoonful.
• Perfect for Any Occasion: Whether you’re hosting a summer BBQ, baby shower, or just baking for fun, these cupcakes add a pop of color and flavor to the table.
• Easy to Make: You don’t need fancy equipment or complex steps—just a bowl, whisk, and a few pantry staples (plus those magical key limes).

Ingredient List

For the Key Lime Cupcakes:

• 1 ½ cups all-purpose flour
• 1 ½ teaspoons baking powder
• ¼ teaspoon salt
• ½ cup unsalted butter, softened
• 1 cup granulated sugar
• 2 large eggs
• 2 tablespoons key lime zest (about 4–5 key limes)
• ¼ cup fresh key lime juice
• ½ cup whole milk
• 1 teaspoon vanilla extract

For the Key Lime Frosting:

• ½ cup unsalted butter, softened
• 4 oz cream cheese, softened
• 2 tablespoons key lime juice
• 1 teaspoon key lime zest
• 3–3 ½ cups powdered sugar (adjust for consistency)
• Pinch of salt

Ingredient Notes

• Key Limes: Fresh is best! Key limes are smaller and more aromatic than regular limes. The juice and zest are what really make these cupcakes pop.
• Butter: Make sure it’s fully softened for easy creaming—it creates that light, fluffy texture.
• Cream Cheese: Use full-fat cream cheese for a richer, smoother frosting.
• Zest Before Juicing: Always zest your limes before cutting them—it’s way easier and ensures you get all that fragrant oil.
• Powdered Sugar: Start with 3 cups and add more as needed to reach your desired frosting thickness.

Kitchen Equipment Needed

• Mixing Bowls (at least 2): One for dry ingredients, one for wet—helps keep things organized.
• Electric Mixer or Stand Mixer: For creaming the butter and sugar until fluffy. I love using my hand mixer for easy cleanup.
• Zester or Microplane: Essential for getting all that fragrant key lime zest.
• Citrus Juicer: Makes squeezing those tiny key limes so much easier and faster.
• Cupcake Pan + Liners: Standard 12-cup pan. Liners help with easy removal and cleaner presentation.
• Rubber Spatula: Perfect for scraping down the sides of the bowl and folding ingredients gently.
• Piping Bag + Tip (optional): For a neat, bakery-style frosting finish. You can also just use a zip-top bag with the corner snipped!

Instructions

Step 1: Preheat and Prep Your Pan

• Preheat your oven to 350°F (175°C).
• Line a standard 12-cup cupcake pan with paper liners.
• Set aside while you make the batter.

Pro Tip: If you want domed cupcakes, don’t open the oven door during the first 12 minutes of baking—this helps them rise evenly.

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Step 2: Mix the Dry Ingredients

• In a medium bowl, whisk together:
  • 1 ½ cups all-purpose flour
  • 1 ½ teaspoons baking powder
  • ¼ teaspoon salt
• Set aside.

This step ensures your leavening is evenly distributed before combining with wet ingredients.

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Step 3: Cream the Butter and Sugar

• In a large mixing bowl, add:
  • ½ cup softened unsalted butter
  • 1 cup granulated sugar
• Beat on medium-high speed for 2–3 minutes, until light and fluffy.

Pro Tip: Proper creaming helps create air pockets that give your cupcakes a soft, tender crumb. Don’t rush this part!

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Step 4: Add Eggs, Lime Zest, and Vanilla

• Add in:
  • 2 large eggs (one at a time), beating well after each.
  • 2 tablespoons key lime zest
  • 1 teaspoon vanilla extract
• Mix until fully combined and smooth.

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Step 5: Add Lime Juice and Milk

• Reduce mixer speed to low.
• Add ¼ cup key lime juice. (The batter may look slightly curdled—totally normal!)
• Slowly pour in ½ cup milk and mix just until blended.

Pro Tip: Don’t overmix after adding the liquid ingredients; it can make the cupcakes dense.

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Step 6: Combine Wet and Dry

• Add the dry ingredients to the wet in two parts.
• Use a spatula or low mixer speed to gently mix until just combined—no dry streaks should remain.

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Step 7: Fill and Bake

• Divide the batter evenly among the 12 cupcake liners—about ¾ full each.
• Bake for 18–22 minutes, or until a toothpick inserted in the center comes out clean.

Pro Tip: Rotate the pan halfway through baking for even browning, especially if your oven has hot spots.

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Step 8: Cool Completely

• Let the cupcakes cool in the pan for 5 minutes.
• Then transfer to a wire rack and allow to cool completely before frosting.

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Step 9: Make the Frosting

• In a bowl, beat together:
  • ½ cup softened butter
  • 4 oz softened cream cheese
• Beat until smooth and fluffy—about 2–3 minutes.
• Add:
  • 2 tablespoons key lime juice
  • 1 teaspoon key lime zest
  • Pinch of salt
• Slowly beat in 3–3 ½ cups powdered sugar until your frosting is thick and spreadable.

Pro Tip: If it’s too thick, add a tiny splash of milk or lime juice. Too thin? Add more powdered sugar a few tablespoons at a time.

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Step 10: Frost and Garnish

• Pipe or spread frosting onto fully cooled cupcakes.
• Garnish with a little extra lime zest or a thin lime slice for a cute finish.

And you’re done! Bright, citrusy perfection in cupcake form.

Tips and Tricks for Success

• Use fresh key limes whenever possible. Bottled juice works in a pinch, but nothing beats the brightness of freshly squeezed juice and zest.
• Room temperature ingredients make a big difference. Cold butter or eggs can lead to lumpy batter and uneven baking.
• Zest before juicing. It’s nearly impossible to zest a lime after it’s been cut, so always zest first.
• Don’t overmix the batter. Once you add the flour, mix just until everything is combined to avoid dense cupcakes.
• Cool completely before frosting. Even slightly warm cupcakes can melt your frosting and turn it into a mess.

Ingredient Substitutions and Variations

• No key limes? Use regular Persian limes if you must, but reduce the zest slightly since they’re stronger in flavor.
• Dairy-free version: Swap butter with a plant-based butter and use a dairy-free milk like almond or oat. Use vegan cream cheese for the frosting.
• Add coconut: Mix shredded coconut into the batter or sprinkle on top of the frosting for a tropical twist.
• Make it into a cake: Pour the batter into an 8-inch round pan and bake for 25–28 minutes for a single-layer cake version.
• Mini cupcakes: Use a mini muffin pan and reduce bake time to about 10–12 minutes. Great for parties or dessert platters!

Serving Suggestions

• Perfect for summer gatherings: These cupcakes are a hit at BBQs, picnics, or poolside parties. They’re light, refreshing, and easy to grab and go.
• With a tropical twist: I love topping each cupcake with a sprinkle of toasted coconut or a dollop of whipped cream for a piña colada-inspired vibe.
• As a birthday treat: Skip the traditional cake and serve a tray of these with fun lime slice toppers or colorful sprinkles—festive and unique!
• With coffee or tea: The citrusy flavor pairs so well with a cup of Earl Grey or light roast coffee—perfect for an afternoon pick-me-up.
• Chilled on a hot day: Pop them in the fridge for 20–30 minutes before serving. The cool frosting and tangy lime flavor hit differently when chilled!

Storage and Reheating Instructions

• Room temperature: Store unfrosted cupcakes in an airtight container for up to 2 days.
• Refrigerated: Frosted cupcakes can be kept in the fridge for up to 4–5 days. Just let them sit at room temp for 15–20 minutes before serving.
• Freezer-friendly: Freeze unfrosted cupcakes for up to 2 months. Wrap tightly in plastic wrap and place in a zip-top bag. Thaw at room temp.
• Frosting storage: Extra frosting? Store it in the fridge for up to a week. Re-whip before using to bring it back to a smooth consistency.
• Avoid microwaving: Reheating cupcakes in the microwave can dry them out. Instead, let them naturally come to room temperature for best texture.

Frequently Asked Questions

Can I use bottled key lime juice instead of fresh?

Yes, you can! While fresh juice gives the best flavor, bottled key lime juice (like Nellie & Joe’s) works well if you’re short on time or fresh limes.

What’s the difference between key limes and regular limes?

Key limes are smaller, more aromatic, and slightly sweeter than regular Persian limes. They have a distinct tang that makes these cupcakes really shine.

Can I make these cupcakes ahead of time?

Absolutely! Bake the cupcakes a day ahead and store them unfrosted at room temperature. Frost the next day for the freshest taste and texture.

Can I turn this into a cake?

Yes! Pour the batter into an 8-inch round or square pan and bake for 25–28 minutes. Same flavor, just in cake form.

How do I keep my frosting from melting?

Make sure your cupcakes are completely cool before frosting, and keep them in a cool room or refrigerated until ready to serve—especially in warm weather!

Can I make them gluten-free?

Yes, just use a good 1:1 gluten-free flour blend in place of regular flour. Cupcakes may be slightly more delicate, but still delicious.

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Did you try this recipe? Let me know in the comments how it turned out!

Don’t forget to share your photos on Instagram and tag me @tasiahub_ or use the hashtag #tasiahub. I’d love to see your creations!