Boxed cake mix is given a tangy twist with a creamy Key lime filling. This easy to make Key Lime Poke Cake is a great potluck dish, and you can even make the filling green for a fun St. Patrick’s Day treat!
I absolutely love all things sour and tangy, so of course Key lime pie is one of my favorite desserts. This Key Lime Poke Cake is sort of a hybrid between Key lime pie and cake – a mashup of two amazing desserts! I adapted this recipe from Betty Crocker, and turned the tartness and lime flavor up to suit my love of all things sour! Don’t get me wrong, this cake is still plenty sweet, and it’s topped with fluffy, slightly sweetened whipped cream that helps to balance the whole dessert out.
Here are all the reasons why you NEED this dessert in your life:
- It uses boxed cake mix so it’s super easy to make, but the Key lime filling and homemade whipped cream elevate the cake into something unique and special!
- Since the cake is baked in a 9 x 13 inch pan, it’s great for potlucks and travels well.
- This cake is versatile and delicious for all seasons! The lime flavors make for a great spring or summer treat; you can even use food coloring to dye the Key lime filling green for St. Patrick’s Day. And, since you can use bottled key lime juice and regular limes, you can still get your Key lime fix even in the dead of winter!
Here are all the ingredients you will need to make Key Lime Poke Cake:
- Boxed white cake mix: plus all the ingredients called for on the box. I used whole eggs in my mix rather than just whites, so my final cake came out a little yellow. If you want a pure white cake, use only egg whites!
- Key lime juice: I wanted this recipe to be as accessible as possible for all seasons and locations, so I used bottled Key lime juice. And in my opinion, it gives the filling that classic diner Key lime pie flavor (which I love!). If you have fresh Key limes and want to make your own juice though, go for it! You can also substitute regular lime juice for the Key lime if you need to; the flavor isn’t exactly the same but it will still taste good!
- Limes: I used regular limes for the lime zest. The recipe calls for 2 tsp. lime zest, about 1 – 1 ½ limes. If you’ve got Key limes, go ahead and use those for the zest also!
- Sweetened condensed milk: this provides sweetness to the filling and also helps recreate that Key lime pie sensation.
- Evaporated milk: unlike the condensed milk, this is unsweetened. It helps to thin out the filling and adds some additional richness without being too heavy.
- Food coloring: this is optional. I wanted to go for a St. Patrick’s Day thing, so I went heavier with the food coloring than I would normally. In order to get that limey-type green, you’ll need both green and yellow. I used 5 drops yellow and 3 green, but you may vary this depending on your own tastes and brand of food coloring!
- Heavy whipping cream: this is for the whipped cream topping.
- Granulated sugar: just a bit to add to the whipped cream topping.
- Extra limes for garnish: this is optional! For decoration, you can add some thinly sliced limes on the top, and/or add some additional lime zest. Feel free to use either regular or Key limes for this.
Use a large diameter wooden spoon handle
Using a large diameter tool to poke the holes is very important! If you use something smaller in diameter like a skewer, the filling won’t be able to penetrate the cake and will mostly sit on top. You want to make sure enough of the Key lime flavor gets into the cake! This also helps the cake stay super moist. I used the handle of a wooden spoon that was about ½ inch in diameter.
Make deep holes
Also, when making the holes, push the handle all the way down into the bottom of the cake, and give the wooden spoon handle a bit of a twist before pulling it out of the cake. This will ensure the holes are made all the way down and will reduce the amount of loose crumbs created.
Don’t worry about filling leaking through the bottom of the cake; the filling is quite thick so I found that even when I poked the holes all the way down, the filling still didn’t make it all the way to the bottom. So, the deeper the holes, the more filling in the cake!
Spread the filling across the cake with a rubber spatula
Spread the filling across the surface of the cake with a rubber spatula, almost pressing the filling down into the holes. This ensures the filling really gets all the way down into the holes. And don’t forget to spread it all the way down the edges of the cake too. (The edge pieces are the best part for that reason – extra filling!)
Let the filling set all the way before adding the whipped cream
After you spread the Key lime filling on the cake, you will need to let the filling set up in the fridge for about 2 hours, loosely covered. I say loosely covered because having a bit of air circulating helps the filling set up as some of the moisture evaporates from the surface. You can also let it stay in the fridge for up to one day before frosting!
Allowing the cake to hang out in the fridge for awhile allows the filling to sink deeper into the cake, and it will also be easier to frost since the top won’t be super wet. If you touch your finger lightly to the surface of the cake and it feels slightly tacky, rather than sticky and wet, then you are good to go and can add the whipped cream.
If you’ve tried this recipe for Key Lime Poke Cake, please let me know what you thought about it in the comments down below, I would love to hear from you! You can also follow me on Facebook, Instagram and Pinterest to see more delicious recipes from Nibble and Dine!
And if you love easy dessert recipes as much as I do, check out some of my other favorite recipes here:Print
An intensely lime-y and luscious dessert that’s super easy to make! White boxed cake mix is filled with tangy Key lime filling and topped with whipped cream.
- 1 box white cake mix, plus ingredients listed on the box
- 1 14 oz. can sweetened condensed milk
- 1 12 oz. can evaporated milk
- ⅔ c. Key lime juice (bottled or fresh)
- yellow and green food coloring (optional, see note)
- 2 tsp. lime zest, plus more for garnish
- 2 c. heavy whipping cream
- 2 tbsp. granulated sugar
- slices of lime (for garnish, optional)
1. Prepare the white cake in a 9 x 13 inch pan, as directed on the box. Let cool for 5 – 10 minutes.
2. Using the handle of a wooden spoon, poke holes in the cake about 1 inch apart. For best results, use a handle with a diameter of approximately ½ inch, going all the way down to the bottom of the cake. If the holes are too small, the filling won’t penetrate the cake and will just sit on top.
3. In a medium bowl, whisk together the sweetened condensed milk, evaporated milk and lime zest. Add the Key lime juice and optional food coloring, whisk to combine. (The mixture will thicken immediately after the lime juice is added, don’t worry this is normal!)
4. Immediately pour the Key lime filling over the cake and, using a rubber spatula, spread the filling across the surface and down around the sides of the cake, making sure all the holes are filled.
5. Loosely cover the cake with tin foil or plastic wrap and place in the refrigerator for 2 hours, or up to 1 day. During this time, the filling will further soak into the cake and firm up. Once the filling has firmed up and is no longer wet on the surface of the cake, the whipped cream topping can be applied.
6. To make the whipped cream topping, add the heavy whipping cream and granulated sugar to a large bowl or the bowl of a stand mixer. Beat with hand beaters or the whip attachment of the stand mixer until whipped cream has formed stiff peaks (about 3 – 4 minutes on high speed).
7. Spread the whipped cream on the cake. Serve immediately, garnished with additional lime zest and slices of lime (optional).
- To get the green color you see in the blog photos, I used 5 drops yellow food coloring and 3 drops green. For a more “natural” look, reduce the amount of food coloring. And, it’s important to note that different brands of food coloring can have different results, so start small and add more if needed. Or, leave the food coloring out all together, the choice is yours!
- The cook time listed for the cake is an approximation to give an idea of how long the entire recipe will take to make start to finish. To bake the cake, please follow the directions on the box!
- Recipe adapted from Betty Crocker.
Keywords: Key lime poke cake, lime poke cake, Key lime cake, lime cake, box cake recipes, easy Key lime poke cake, St. Patrick’s Day cake, St. Patrick’s Day dessert