Irresistible 5-Star Key Lime Sheet Cake Recipe Under 30 Min

Name: Irresistible 5-Star Key Lime Sheet Cake Recipe Under 30 Min
Prep time: 15 min
Cook time: 25 min
Total time: 40 min
Cuisine: American
Ingredients: 2 cups all-purpose flour; 1 1/2 cups granulated sugar; 1 tsp baking powder; 1/2 tsp baking soda; 1/2 tsp salt; 4 large eggs; 1/2 cup unsalted butter, melted; 1/2 cup sour cream; 1/4 cup key lime juice; 1 tbsp key lime zest; 1 tsp vanilla extract

Author: Sarah

Published: July 25, 2025

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There’s nothing quite like that first bite of a perfectly tangy, sweet key lime sheet cake to transport you straight to summer – no matter what season it is. I first fell in love with this recipe when my neighbor Mrs.

Thompson brought over a still-warm slice after we helped her move. That perfect balance of bright citrus and buttery cake had me begging for the recipe before I’d even finished my piece! What makes this key lime sheet cake recipe special isn’t just its refreshing flavor (though that’s definitely a big part), but how foolproof it is. Whether you’re feeding a crowd at a potluck or just craving something sunny and sweet, this cake delivers every time. The best part? It comes together in about the same time it takes to watch your favorite sitcom episode.

Table of contents:

Why You’ll Love This Key Lime Sheet Cake Recipe

This isn’t just any cake—it’s the kind of dessert that makes people ask for seconds before they’ve even finished their first slice. Here’s why it’s become my go-to for everything from backyard BBQs to last-minute cravings:

Effortless baking: No fancy techniques needed—just mix, pour, and bake. Even my 10-year-old niece can make this without a hiccup.
That perfect tang: Fresh key lime juice and zest give it that bright, citrusy punch that’ll wake up your taste buds in the best way.

Always a hit: I’ve brought this to countless gatherings, and every time, someone whispers, “You have to give me the recipe.”
Moist for days: Thanks to the sour cream in the batter, this cake stays wonderfully tender—if it even lasts long enough to test that theory!

Trust me, once you try this recipe, you’ll understand why I always keep key limes in my fridge now.

Ingredients for Key Lime Sheet Cake Recipe

Gathering these simple ingredients is the first step to citrusy bliss—and I promise, nothing here is hard to find. I’ve made this cake more times than I can count, and here’s what you’ll need to make the magic happen:

2 cups all-purpose flour: Spoon it into your measuring cup and level it off for perfect results every time.
1 1/2 cups granulated sugar: Just enough sweetness to balance that tangy lime kick.

1 tsp baking powder + 1/2 tsp baking soda: Our little rising heroes—make sure they’re fresh!
1/2 tsp salt: Trust me, it makes all the flavors pop.
4 large eggs: Room temperature eggs blend smoother—I leave mine out while preheating the oven.

1/2 cup unsalted butter, melted: That golden richness is non-negotiable in my book.
1/2 cup sour cream: The secret to that melt-in-your-mouth texture.
1/4 cup key lime juice, freshly squeezed: Bottled works in a pinch, but fresh is brightest—I roll my limes first to get every last drop!

1 tbsp key lime zest: Those vibrant green flecks = maximum flavor bombs.
1 tsp vanilla extract: A warm background note that somehow makes the lime sing louder.

See? Nothing crazy—just honest ingredients that come together to create something magical. Now let’s get mixing!

Equipment Needed

You won’t need any fancy gadgets for this key lime sheet cake—just the basics from your kitchen that you probably already have! Here’s my go-to setup:

9×13-inch sheet pan: My trusty metal one gives the perfect golden edges.
Mixing bowls: Two medium ones—one for dry ingredients, one for wet.

Whisk and spatula: The whisk for blending, spatula for scraping every last bit of batter.
Measuring cups/spoons: Because eyeballing never works with baking!
Zester/microplane: For getting that perfect lime zest without the bitter pith.

That’s it—now you’re ready to bake up some sunshine!

How to Make Key Lime Sheet Cake Recipe

Alright, let’s get baking! This key lime sheet cake comes together so easily you’ll wonder why you don’t make it every week. I’ve walked countless friends through these steps, and they’re always shocked at how simple it is to get such amazing results. Here’s exactly how I do it:

Preparing the Batter

First things first—preheat that oven to 350°F (175°C). While it’s heating up, grab your sheet pan and give it a quick grease. I like to use butter or baking spray, making sure to get into all the corners.

Now for the dry ingredients: In a medium bowl, whisk together the flour, sugar, baking powder, baking soda, and salt. A little tip I learned the hard way? Whisk them really well so everything gets evenly distributed—no one wants a bite with too much baking soda!

In another bowl (this is where my trusty glass measuring cup comes in handy), beat the eggs lightly before adding the melted butter, sour cream, key lime juice, zest, and vanilla. The mixture will look a bit curdled at first—that’s totally normal, don’t panic! Just keep whisking until it comes together.

Here’s the important part: gradually add the dry ingredients to the wet ingredients, stirring just until combined. Overmixing is the enemy here—a few small lumps are way better than a tough cake. The batter should be thick but pourable, with the most beautiful pale yellow-green color from all that bright lime zest.

Baking and Cooling

Pour that gorgeous batter into your prepared pan, using a spatula to spread it evenly into the corners. The oven should be nice and hot by now—slide that pan in and set your timer for 25 minutes.

At the 25-minute mark, do the toothpick test: stick it in the center of the cake. If it comes out with a few moist crumbs clinging to it, you’re golden! If it’s still wet, give it another 2-5 minutes. Mine usually takes about 28 minutes, but ovens can vary.

Here’s where patience comes in—let the cake cool completely in the pan on a wire rack. I know, I know, it smells amazing and you want to dive right in, but trust me, letting it cool makes all the difference in texture. If you’re adding frosting, this is the perfect time to whip it up while you wait.

And that’s it! You’ve just made a key lime sheet cake that’ll have everyone thinking you spent hours in the kitchen. Now the only hard part is deciding whether to share… Follow me on Pinterest for more delicious recipes!

Tips for Perfect Key Lime Sheet Cake Recipe

After making this cake more times than I can count, I’ve learned a few tricks that take it from good to “oh-my-goodness-I-need-another-slice” amazing:

Zest first, juice later: Always zest your limes before juicing them—it’s way easier! And don’t skimp on the zest—that’s where the real lime flavor lives.
The toothpick lie: Your cake might look done at 20 minutes, but that toothpick doesn’t lie. Wait until it comes out with just a few moist crumbs to avoid a dry cake.
Sour cream swap: Out of sour cream? Plain Greek yogurt works beautifully in a pinch—I’ve used both with equally delicious results.

Color trick: For an extra vibrant green hue (great for St. Patrick’s Day!), add just a drop or two of food coloring to the batter.

Remember—baking is part science, part love. Don’t stress if your first try isn’t perfect. Mine certainly wasn’t!

Serving Suggestions

This key lime sheet cake shines bright on its own, but oh boy—wait till you see what happens when you dress it up! My favorite way? A generous dollop of barely-sweetened whipped cream and handful of fresh raspberries that burst against the tangy lime. For an extra pretty touch, I sometimes dust the top with powdered sugar right before serving—the white snow against the vibrant green zest looks stunning. And if we’re feeling fancy? A scoop of vanilla bean ice cream melting into the warm cake is absolute heaven.

Storage and Reheating

Here’s the beautiful thing about this key lime sheet cake—it actually gets better the next day as the flavors mingle! I just cover the pan tightly with foil or transfer slices to an airtight container (if they last that long). It keeps beautifully at room temperature for 2-3 days. For longer storage, you can refrigerate it up to 5 days, but honestly? It’s always gone before then in my house. If you want to enjoy it warm, just pop a slice in the microwave for 10-15 seconds—it’ll taste fresh from the oven all over again!

Nutritional Information

Each slice of this sunshine-filled cake comes in at about 280 calories – just enough to satisfy that sweet tooth without going overboard. Remember, these numbers are estimates and can vary depending on your exact ingredients. The tart lime juice and zest give you a little vitamin C boost too – not that we’re calling this health food, but hey, every bit counts when it tastes this good!

FAQs About Key Lime Sheet Cake Recipe

Can I use regular limes instead of key limes?
Yes, but there’s a difference! Regular limes (Persian limes) are less tart and aromatic than key limes. If substituting, use the same amount of juice but add an extra teaspoon of zest. The flavor won’t be exactly the same—my neighbor swears by Meyer lemons for a fun twist—but it’ll still be delicious.

How do I prevent my cake from turning out dry?
Three golden rules: 1) Don’t overbake—set a timer! 2) Measure flour correctly (spoon and level). 3) Use full-fat sour cream—low-fat versions don’t provide the same moisture. If your cake still feels dry, try brushing cooled slices with a simple syrup made with key lime juice and sugar.

Can I make this into cupcakes?
Absolutely! Fill lined cupcake tins 2/3 full and bake at the same temperature for 18-22 minutes. They’re adorable with a swirl of cream cheese frosting and a thin lime slice on top—perfect for summer parties.

Why did my cake sink in the middle?
Usually it’s because the oven door was opened too early, or the baking powder/soda was old. Always test freshness by dropping a bit into hot water—if it fizzes vigorously, you’re good to go!

I’d love to hear how your key lime sheet cake turns out! Leave a comment below with your baking triumphs (or funny flops)—I read every one. Tag me on social media too so I can cheer you on!