
My go-to summer treat is this bright green, zesty lime cake. Everyone loves how the light, airy texture works with the smooth lime frosting - it's got that perfect sweet-tart combo that gets people coming back for seconds.
The first time I whipped this up was for my sister's backyard bash last year. It was such a winner that now I can't show up to any summer get-together without it. Folks get excited just seeing that vibrant green color before they even taste it.
Ingredients
For the Cake
- Large eggs: they should be room temp to help the cake rise evenly and give it structure
- Milk: brings moisture and makes the crumb nice and tender
- Vegetable oil: keeps everything more moist than if you used butter
- Fresh lime juice: gives that zippy tang this cake is known for
- Lime zest: packs those natural oils that really punch up the citrus flavor
- Lime flavored gelatin powder: boosts both the green look and lime taste
- All purpose flour: nothing fancy needed for this treat
- Granulated sugar: cuts through the lime's sourness
- Baking powder: gives just enough lift to make it fluffy
- Salt: brings out all the good flavors and tones down sweetness
For the Lime Frosting
- Sweetened condensed milk: makes for a super creamy foundation
- Fresh lime juice: balances the sweetness with a bit of tang
- Lime flavored gelatin powder: makes both the color and flavor pop more
- Hot water: makes sure the gelatin melts fully
Step-by-Step Instructions
- Prepare Your Pan:
- Get your 8 inch square pan ready with parchment paper, leaving some hanging over the sides so you can lift the cake out easily later. Heat your oven to 350°F. Getting the temp right means your cake will bake evenly and have the best texture.
- Mix Wet Ingredients:
- Beat those eggs for a full minute to get air in there. This makes your cake fluffier. Then add your milk, oil, lime juice, zest, and gelatin powder, and whisk it all together. Don't worry if it looks a bit curdled - that's just the lime juice reacting with the milk.
- Combine Dry Ingredients:
- Grab a sifter and add the flour, sugar, baking powder, and salt right over your wet stuff. Sifting stops lumps and spreads everything evenly. Stir just enough to mix it all together. Once you can't see flour anymore, stop stirring or your cake might end up tough.
- Bake To Perfection:
- Pour everything into your pan and bake for 30 minutes on the dot. You'll know it's done when it bounces back after a light touch and a toothpick comes out mostly clean. Let it cool completely before you add frosting.
- Prepare The Frosting:
- Mix the condensed milk and lime juice until smooth. You'll notice it starts to get thicker right away because the lime's acidity works on the milk. This reaction makes it just right for spreading.
- Add Gelatin:
- Stir the lime gelatin into hot water until you can't see any little bits anymore. Mix this into your milk mixture and stir well so the color and flavor spread throughout.
- Frost And Chill:
- Spread your frosting all over the cooled cake. A flat spatula works best for a smooth top. Pop it in the fridge for at least 2 hours so the frosting can set up nicely.

The lime gelatin is what makes this cake stand out from regular citrus cakes. When my mom first watched me dump it in the batter, she wasn't sure about it. Now she's always asking for the recipe to pass to her friends.
Storage Tips
Keep this cake in the fridge in something airtight and it'll stay good for 5 days. The frosting actually tastes better after a day when all the flavors have had time to mingle. I usually wrap any cut sides with plastic to keep them from drying out.
Seasonal Variations
When limes are really good in summer, I sometimes put a layer of sliced strawberries between the cake and frosting. It looks amazing with the color contrast and tastes even better. In the winter months, try using lemons instead for a brighter taste that works well after heavy holiday food.
Serving Suggestions
Want to make it look fancy? Put a small lime wedge and mint leaf on each slice right before you serve it. This cake goes great with plain vanilla ice cream or some lightly sweetened whipped cream. At summer parties, I serve it with fresh berries and cold prosecco on the side.
The History Behind The Green
This type of cake comes from traditional Florida Key lime desserts, but that eye-catching green color started during the 1950s and 60s when gelatin desserts were all the rage. I've taken the old-school recipe and updated it with fresh stuff while keeping that fun, nostalgic green color that gets everyone excited.

Recipe FAQs
- → Can I use bottled lime juice instead of fresh?
Fresh lime juice gives this cake its best flavor punch, but bottled juice can work too. Just know the taste won't be as bold, and you'll miss those nice-smelling oils from fresh limes. If you go with bottled stuff, maybe toss in some extra grated peel to make up for what you're missing.
- → What can I substitute for lime-flavored gelatin?
Can't find lime gelatin? Try plain gelatin plus more lime peel and a touch of green food color. Want to go natural? Agar-agar powder works in the same amount, though your cake might feel a bit different when you bite into it.
- → Can this cake be made in advance?
You bet! This cake actually tastes better the next day. All those flavors mix together nicely and the topping firms up perfectly when left in the fridge overnight. Just wrap it up and keep it cold for up to 3 days.
- → Why did my frosting not set properly?
Your topping needs two things to set right: fully melted gelatin and enough cold time. Make sure your gelatin completely dissolves in hot water before you mix it with the milk stuff. Then give it at least 2 hours in the fridge. The sour lime juice also helps thicken that sweet condensed milk.
- → Can I make this cake in a round pan instead?
Sure thing! An 8-inch or 9-inch round pan works just fine instead of the square one. Just watch your baking time since it might change a bit with a different shaped pan. You'll know your cake is done when you stick a toothpick in the middle and it comes out clean.
- → Is there a dairy-free version of this cake?
You can make this cake without dairy by swapping regular milk for almond, soy, or coconut milk. For the topping, try coconut condensed milk instead of the regular kind. Just know these swaps will change the taste a bit, with coconut milk adding a nice tropical feel that goes well with lime.