I made this Easy Key Lime Cake with Boxed Mix for my son’s 20th birthday, and it turned out to be the perfect celebration cake. He’s always been a big fan of key lime pie, so I knew he’d love the bright citrus flavor paired with fluffy whipped cream. With layers of buttery golden cake, tangy lime filling, and a light, creamy topping, it’s a refreshing twist on a classic dessert that your whole family will enjoy too.

Key lime cake on serving plate with decorative whipped cream border and fresh lime wedges.

A refreshing dessert that’s as beautiful as it is delicious. Made easy with a cake mix, this naked layered cake is light, tangy, and perfect for any party. Topped with fluffy key lime whipped cream and garnished with fresh lime slices, it’s a show-stopping cake that’s easier to make than it looks!

Slice of key lime cake showing four layers with whipped cream filling and lime garnish.

Why You’ll Love Easy Key Lime Cake with Boxed Mix

• This cake is bursting with bright lime flavor and creamy layers.

• Using a cake mix as the base makes it quick and easy, while the homemade key lime whipped cream filling gives it a bakery-quality finish.

• It’s perfect for birthdays, potlucks, holidays, or any gathering that calls for a special dessert.

What You Need

ngredients for key lime layer cake including cake mix, instant pudding, key lime juice, sweetened condensed milk, and heavy cream

Ingredient Notes

• Cake mix: Using a butter golden cake mix keeps this recipe simple while still producing a rich, moist cake.
• Key lime juice: Fresh key limes are wonderful if you can find them, but bottled key lime juice works just as well.
• Sweetened condensed milk: Essential for creating that smooth, creamy lime filling.
• Whipped cream: Use heavy whipping cream and beat until stiff peaks form - it adds a light, airy texture to the filling.
• Garnish: Lime triangles make the cake look extra festive and hint at the citrus flavor inside.

Step-by-step photo collage showing how to bake cake layers, make lime filling, assemble, and decorate a key lime layer cake

How You Make Easy Key Lime Cake with Boxed Mix

• Start by baking two round cake layers using your cake mix and added ingredients indicated in recipe below.

• Once cooled, slice each cake in half to create four thin layers.

• Whip up a filling by combining sweetened condensed milk, lime juice, and whipped cream. Then layer everything together, alternating cake and filling.

• Finish with piped whipped cream on top and a garnish of lime wedges. Refrigerate before serving to let the flavors meld.

Close-up of moist key lime cake layers with creamy whipped filling and tangy lime flavor.

Frequently Asked Questions

• Can I use regular limes instead of key limes? Yes! I actually used regular limes for the fresh juice in the cake batter and bottled key lime juice for the filling. You can use bottled juice for both parts of the cake, fresh limes for both, or mix and match - whatever is easiest for you.

• Can I make this ahead of time? Absolutely! In fact, the cake tastes even better the next day as the lime flavor deepens.

• Do I need to cut the cake into four layers? You don’t have to, but creating thinner layers gives you more filling-to-cake ratio and a prettier presentation.

• Can this cake be frozen? Yes, freeze the unfilled cake layers, then thaw and assemble with filling and frosting when ready to serve.

Whole key lime layer cake topped with whipped cream swirls and lime wedges on a cake stand.

Quick Tips

• Use room temperature eggs for best cake texture.
• Don’t overmix the batter, which can make the cake dense.
• Chill the bowl and beaters before whipping cream for faster, fluffier peaks.
• Refrigerate the cake for at least 2 hours before serving for clean slices and set layers.

Overhead view of key lime layer cake decorated with piped whipped cream and lime triangles.