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This easy sour cream coconut cake, also known as 3-day coconut cake, pairs a simple butter cake with a filling and frosting made from sour cream, coconut, and whipped topping. After resting in the refrigerator for 3 days, the resulting cake is super moist, tender, and delicious!
What is 3-day coconut cake?
If you’ve been reading MBA for a while, you might remember that I used to be a teacher many years ago.
Back in 2013, I was given this recipe by the secretary of the school I worked at. She would make this sour cream coconut cake recipe for all of our staff potlucks, and everyone would go bananas over it.
Obviously I had to have the recipe, and imagine my surprise when I finally read the method for making this cake.
This recipe is sometimes known as a 3-day coconut cake because that’s how long it needs to chill in the refrigerator after assembling and before serving. You make the cake, fill and frost it with a mix of sour cream, coconut, and whipped topping, and then let it hang out in the fridge for 3 days.
Something totally magical happens during those 3 days. The cake becomes perfectly moist (but not soggy) and ultra flavorful. The sour cream makes it tangy but it’s still sweet. It might be the best coconut cake I’ve ever had.
Jamie’s testing notes
- Let the cake rest for the full 3 days for the best flavor and texture. It’s still good when served before the 3-day mark, but it’s definitely best when you wait the 3 days. Your patience will be rewarded!
- I prefer using the Duncan Hines Butter Cake mix to yellow cake mix. I’ve tried the recipe with both, and I found the butter cake to be just a bit richer and more delicious. You could try using a white cake mix, but I don’t recommend it. The richness of the butter cake holds up better to the filling and frosting.
- You have to use sweetened coconut in this recipe. This is not a place where you can get away with using unsweetened coconut. Save that for your chewy lime sugar cookies. In this recipe, you must have the sweetened coconut in order for the filling and frosting to taste right.
Ingredient notes
⬇️ For the full recipe, including ingredient amounts, scroll down to the recipe card below!
- Butter cake mix & the ingredients to make it: I prefer to use the Duncan Hines mix, but you can use any butter cake mix brand you like as long as it is 15.25 ounces. You’ll need the associated ingredients to make the cake according to the package directions.
- Sour cream: This is not the place to use reduced-fat sour cream or swap for Greek yogurt. For the best flavor, use regular sour cream.
- Granulated sugar: To help sweeten the filling and frosting.
- Sweetened flaked or shredded coconut: This is is going to give the cake its coconut flavor. As I mentioned above, you must use sweetened coconut, not unsweetened.
- Whipped topping: Such as Cool Whip. Thaw it according to the package directions before using.
How to make this sour cream coconut cake recipe
Start by preparing the cake mix according to the package directions, then divide the cake batter into two 8-inch round cake pans. I don’t recommend using 9-inch pans—the resulting cake layers will be thinner and much harder to split in half later.
Once the cakes are baked and have cooled completely, using a large serrated knife to cut each layer in half horizontally, creating 4 equal layers.
Don’t worry if the layers aren’t perfect. If you want to try to get them as even as possible, this article walks through a few methods for splitting cake layers evenly.
Now it’s time to assemble. Set aside 1/3 cup of the coconut—we’ll use that on top of the cake later.
Mix the rest of the coconut with the sour cream and sugar. Remove 1 cup of this mixture and set it aside for the frosting later.
Use the rest of the sour cream mixture to fill the cake layers. Since there are 4 layers of cake, you’ll put 1/3 of the sour cream mixture for each filling layer.
Now fold that reserved 1 cup of the sour cream mixture and fold it into the Cool Whip and use this to frost the top and sides of the cake. Sprinkle that reserved 1/3 cup coconut on top of the cake.
Loosely cover the cake with plastic wrap or place it into a covered cake carrier. Let it chill in the refrigerator for 3 days before slicing and serving.
Serving suggestions
I think this sour cream coconut cake is perfect as-is, but you could serve individual slices with a dollop of whipped cream and fresh strawberries or blueberries.
Storage tips
After the initial 3-day rest in the refrigerator, store any leftovers covered in the fridge for another 3-4 days.
I don’t recommend storing the in freezer, as freezing and thawing can affect the texture of the filling.
FAQs
This is a bit of an old-fashioned recipe, so some versions of it originally called for frozen sweetened coconut. The brand that most recipes call for (Birds Eye) has since been discontinued. The recipe that my old co-worker gave me always called for the bags of coconut you find in the baking aisle, and they work perfectly in this version of the cake. The coconut flakes soften in the sour cream mixture during the 3-day rest, so the texture is perfect.
Sour Cream Coconut Cake
Ingredients
For the Cake:
- 1 (15.25-ounce) box Duncan Hines Butter Golden Cake mix
- ¾ cup water
- 3 large eggs
- 7 tablespoons unsalted butter melted and cooled
To assemble:
- 16 ounces sour cream
- 1 ½ cups granulated sugar
- 1 (14-ounce) bag sweetened flaked coconut divided use
- 8 ounces frozen whipped topping Cool Whip or Truwhip, thawed
Instructions
- Preheat oven to 350°F. Spray (2) 8-inch cake pans with nonstick cooking spray. Set aside.
- In a large mixing bowl, add the cake mix, water, eggs, and melted butter. Use an electric hand mixer to mix on low speed until the mixture starts to come together, then increase the speed to medium and beat for 4 minutes.1 (15.25-ounce) box Duncan Hines Butter Golden Cake mix, ¾ cup water, 3 large eggs, 7 tablespoons unsalted butter
- Divide the batter between the prepared pans. Bake on the center rack of the preheated oven for 24-28 minutes, or until a toothpick inserted in the center comes out clean.
- Allow cakes to cool in the pan for 15 minutes before turning them out onto a wire rack to finish cooling.
- Once the cakes have cooled completely, use a long serrated knife to split each cake in half horizontally, creating 4 total layers.
- In a large bowl, combine the sour cream and sugar. Set aside ⅓ cup of the coconut and add the rest to the sour cream mixture. Remove 1 cup of the coconut and sour cream mixture and set aside.16 ounces sour cream, 1 ½ cups granulated sugar, 1 (14-ounce) bag sweetened flaked coconut
- Use the remaining coconut and sour cream mixture to frost between each cake layer.
- Fold the reserved sour cream mixture into the whipping topping. Use this to frost the sides and top of the cake. Sprinkle the top of the cake with the reserved ⅓ cup coconut flakes.8 ounces frozen whipped topping
- Cover and refrigerate for 3 days before serving.
Notes
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
