Key Lime Cupcakes

Key Lime Cupcakes bring a bright, tangy twist to the classic cupcake. These treats are soft, moist, and filled with the zesty flavor of key lime juice and zest. Topped with a rich and creamy key lime cream cheese frosting, they offer the perfect balance of sweet and tart. Whether you’re planning a summer picnic or just craving something refreshing, these cupcakes are sure to impress.

Why You’ll Love This Recipe

• Refreshing citrus flavor from real key lime juice and zest
• Soft and moist texture thanks to sour cream in the batter
• A rich, tangy cream cheese frosting that complements the cupcake perfectly
• Great for warm-weather occasions, parties, or casual gatherings
• Easy to customize with garnishes or fillings for added flair

Ingredients

(Tip: You can find the complete list of ingredients and their measurements in the recipe card below.)

For the Cupcakes:

• 1 and 3/4 cups all-purpose flour
• 1 teaspoon baking powder
• 1/2 teaspoon baking soda
• 1/2 teaspoon salt
• 1 cup sour cream
• 1/2 cup unsalted butter, softened
• 1/2 cup granulated sugar
• 1/4 cup light brown sugar
• 1/2 teaspoon key lime extract
• 2 teaspoons key lime zest
• 1 large egg
• 1 egg yolk
• 1 and 1/2 tablespoons fresh key lime juice

For the Frosting:

• 1/2 cup unsalted butter, very soft
• 8 ounces cream cheese, softened
• 4 and 1/2 cups confectioners’ sugar
• 1/4 teaspoon salt
• 1 and 1/2 tablespoons fresh key lime juice
• 1/4 teaspoon key lime extract
• 1 teaspoon key lime zest

For Garnish:

• Key lime zest (optional)

Directions

1. Preheat oven to 350°F (175°C) and line a 12-cup muffin tin with paper liners.
2. In a medium bowl, whisk together flour, baking powder, baking soda, and salt.
3. In a large bowl, beat butter until smooth, then add granulated sugar, brown sugar, lime extract, and zest. Beat until combined.
4. Add the egg and egg yolk one at a time, beating well after each addition.
5. Add half of the dry ingredients, then half of the sour cream, mixing after each addition. Repeat with the remaining dry ingredients and sour cream.
6. Gently fold in the key lime juice until fully incorporated.
7. Divide batter evenly among cupcake liners, filling each about two-thirds full.
8. Bake for 18–22 minutes, or until a toothpick inserted into the center comes out clean.
9. Let cupcakes cool in the pan for 10 minutes before transferring to a wire rack to cool completely.
10. For the frosting, beat butter and cream cheese together until smooth. Gradually add sugar, then mix in salt, key lime juice, extract, and zest until fluffy.
11. Frost cooled cupcakes and garnish with additional lime zest, if desired.

Servings and Timing

• Yield: 12 cupcakes
• Prep time: 20 minutes
• Bake time: 20 minutes
• Total time: 40 minutes

Variations

• Add a graham cracker crust: Line the bottom of each cupcake liner with crushed graham crackers mixed with melted butter for a key lime pie-style base.
• Fill with lime curd: Use a small knife to core the center of each cupcake and fill with homemade or store-bought key lime curd.
• Mini cupcakes: Make bite-sized versions by using a mini muffin tin; reduce baking time to about 10 minutes.
• Toasted coconut topping: Sprinkle toasted coconut over the frosting for a tropical finish.

Storage/Reheating

• Store cupcakes in an airtight container in the refrigerator for up to 3 days.
• Allow cupcakes to come to room temperature before serving for best flavor and texture.
• Unfrosted cupcakes can be frozen for up to 2 months; thaw overnight in the refrigerator before frosting.

FAQs

How are key limes different from regular limes?

Key limes are smaller, more aromatic, and have a more intense tart flavor compared to regular limes.

Can I use regular lime juice instead of key lime juice?

You can, but the flavor will be slightly different. Key limes have a more distinct tartness.

Can I make these cupcakes ahead of time?

Yes, you can bake the cupcakes a day ahead. Store them unfrosted in an airtight container, then frost before serving.

What’s the best way to zest key limes?

Use a microplane or fine grater to zest only the green outer layer, avoiding the bitter white pith.

Can I use bottled key lime juice?

Yes, if fresh key limes aren’t available. Just make sure it’s 100% juice without additives.

Why do my cupcakes sink in the middle?

Overmixing the batter or opening the oven door too early can cause sinking. Mix gently and avoid disturbing the oven.

Can I use low-fat cream cheese for the frosting?

It’s best to use full-fat cream cheese for structure and flavor, but low-fat can be used with slightly different results.

How do I pipe the frosting like a bakery?

Use a piping bag fitted with a large round or star tip and swirl from the outer edge inward.

Can these be made gluten-free?

Yes, substitute a 1:1 gluten-free baking flour for the all-purpose flour.

Are these safe to leave at room temperature?

They can sit out for a few hours, but because of the cream cheese frosting, refrigeration is recommended for longer storage.

Conclusion

Key Lime Cupcakes are a refreshing and vibrant dessert that combines a soft, citrus-infused cake with a creamy, tangy frosting. Whether you’re celebrating a special event or just looking to treat yourself, these cupcakes deliver flavor and elegance in every bite. With simple ingredients and clear steps, they’re a delightful way to bring a touch of the tropics to your table.

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