This delicious refrigerator key lime coconut sheet cake recipe makes every bite of tender yellow cake infused with sweet and creamy lime and coconut flavoring a special treat. Add the homemade whipped topping and I tell you what, you’ve got heaven on a plate.

There is nothing like a nice cold refrigerator cake in the middle of summer heat. This coconut sheet cake recipe features some of my favorite flavors in an ultra-moist cake with a light-tasting homemade whipped cream topping to bring it all together. Are you looking for a showstopper to take to a get-together? This is it! You will be the hit of the party for this one! The fact that it is easy to make and uses easy-to-find ingredients makes it even better.

So, what simple ingredients am I talking about? Well, we start with a boxed cake mix (I’m using Betty Crocker’s yellow cake mix). Then we transform it into a coconut poke cake by poking holes all over its surface and pouring in the most delicious combination of sweetened condensed milk, coconut milk, and lime juice. We set this in the fridge so the cake becomes super tender and soaks up that irresistibly tasty key lime and coconut flavor.

On top, we add a fluffy and refreshing homemade whipped topping made with heavy cream, powdered sugar, coconut milk, and lime juice. If you want to go one step further, add lime zest and sweetened coconut flakes on top. Oh yes, when I say this is bursting with lime and coconut, I’m not lying! Uber moist and rich, this is such a deliciously tropical cake to make this summer that’ll have people lining up at your door.

If you’re looking for more Texas sheet cake recipes to feed a crowd, check out Texas Turtle sheet cake and my Chantilly sheet cake.

Are you ready to try my easy coconut sheet cake? Let’s go!

Recipe Ingredients

Yellow cake mix
Sweetened condensed milk
Coconut milk
Lime juice
Heavy whipping cream
Confectioner’s sugar
Lime zest and shredded coconut flakes (optional)

How to Make Key Lime Coconut Sheet Cake

Preheat oven to 350°.

Spray the bottom only of a 13×9-inch baking dish with nonstick baking spray and flour.

Prepare and bake cake mix in the prepared dish according to package directions.

Let the cake cool for 5 minutes.

In a medium bowl, stir together condensed milk, 1 cup of coconut milk, and 6 tablespoons of lime juice until blended.

Using the handle of a wooden spoon, poke holes in the warm cake, making sure the handle does not touch the bottom of the cake pan.

Pour the coconut mixture over the warm cake.

Cover and refrigerate until chilled (approximately 4 hours).

In a large bowl that’s been chilled, combine cream, confectioners’ sugar, remaining coconut milk, and the remaining 4 tablespoons of lime juice.

Beat at high speed with an electric mixer and chilled beaters just until thickened.

Spread over the cooled cake.

Add lime zest and sweetened coconut flakes on top if using.

Refrigerate until ready to serve.

Storage

Store leftovers in an airtight container in the fridge for up to 5 days.

Recipe Notes

For extra flavor, toast the coconut briefly in the oven before sprinkling the toasted coconut over the iced cake.
Another way to add more flavor is to add 1 teaspoon of vanilla extract and/or 1 teaspoon of coconut extract to the whipped coconut frosting.
Cream of coconut, coconut cream, and coconut milk are not the same things. For best results, you want to use canned coconut milk.
If you want to skip the homemade whipped topping, you can simply use frozen whipped topping like Cool Whip instead.
You can use any kind of cake mix, including white cake mix. You can even make your own cake batter. Check out my pound cake recipe.
Another option is to make a chocolate coconut sheet cake and use a chocolate cake mix.

Recipe FAQs

Can I make coconut sheet cake in advance?

Yes, you can! I’d only make it up to 24 hours in advance though to ensure the whipped topping still looks fresh. Otherwise, make the coconut poke cake up to 2 days in advance and then add the topping the day you’re serving it.

Check out these other coconut treats:

Coconut Meringue Pie

Tropical Dream Bars

Coconut Macaroons Recipe (3 Ingredients Only)

Bon Bons With Coconut

Grandmama’s Coconut Cake With No-Fail Seven-Minute Frosting

Ashley Mac’s Coconut Caramel Pie