Key Lime Cake Recipe Southern Living: Sun-Kissed Citrus Layers With Tangy Frosting

This cake captures the bright, tropical essence of key lime in every moist, tender bite. The layers burst with citrus flavor, perfectly balanced by a creamy, tangy frosting that’s impossible to resist.

What sets this creation apart is its simplicity—no complicated techniques, just a proven method that delivers restaurant-quality results at home. The cake stays soft for days, making it ideal for gatherings or a special treat.

The frosting ties it all together with a smooth, velvety texture and a zesty kick that complements the cake’s subtle sweetness. It’s the kind of dessert that disappears fast.

Serve it chilled for the best experience. Here’s how to make it.

Ingredients for Key Lime Cake Recipe Southern Living

Bright citrus and creamy richness come together in this layered dessert.

The key lime juice is non-negotiable here—freshly squeezed from real key limes (those little yellow-green ones, not regular limes) gives the authentic tropical punch. If you can’t find key limes, Nellie & Joe’s bottled juice is the best store-bought backup. For buttermilk, whole milk plus a splash of vinegar works in a pinch, but full-fat buttermilk delivers the best texture.

No buttermilk? Plain yogurt thinned with milk at a 1:1 ratio gets you close. The cream cheese must be full-fat and block-style—low-fat or tub versions won’t hold up. If key limes are impossible to find, regular lime zest and juice work (use half the amount and add a splash of orange juice for complexity). Always zest limes before juicing them.

The cake stays moist for 3 days at room temperature in an airtight container, or 1 week refrigerated. Frosted cake freezes beautifully for up to 3 months—thaw overnight in the fridge before serving. For best results, serve chilled (the frosting firms up nicely).

Step-by-Step Instructions for Key Lime Cake

Here’s the method I use to achieve perfectly moist layers with vibrant citrus flavor.

Step 1: Prepare the Cake Batter

Preheat your oven to 350°F and grease and flour three 8-inch round cake pans. In a large bowl, sift together the 2.5 cups all-purpose flour, 1 tbsp baking powder, 0.5 tsp baking soda, and 0.5 tsp salt. This ensures even distribution of leavening agents for a consistent rise.

In another bowl, cream the 1 cup unsalted butter with 1½ cups granulated sugar until light and fluffy. Add the 4 whole large eggs one at a time, beating well after each addition. Stir in the 1 tsp vanilla extract, 0.5 cup key lime juice, and 2 tbsp key lime zest for that signature citrus punch.

Alternate adding the dry ingredients and 1 cup buttermilk to the butter mixture, beginning and ending with the dry ingredients. Mix just until combined—overmixing can lead to a dense cake.

Step 2: Bake the Cake Layers

Divide the batter evenly among the prepared cake pans. Bake for 25-30 minutes or until a toothpick inserted into the center comes out clean. The layers should be golden brown and spring back lightly when touched.

Don’t open the oven door too early—this can cause the cakes to sink. Rotate the pans halfway through baking for even browning. Once done, let the cakes cool in the pans for 10 minutes before transferring them to a wire rack to cool completely.

Step 3: Prepare the Cream Cheese Frosting

In a large bowl, beat the 8 oz cream cheese until smooth. Gradually add the remaining ½ cup granulated sugar and beat until creamy. Slowly incorporate the 3 cups powdered sugar, mixing on low speed to avoid a cloud of sugar dust.

If the frosting is too thick, add a splash of buttermilk or key lime juice to reach your desired consistency. The frosting should be smooth and spreadable but hold its shape when piped.

Step 4: Assemble and Frost the Cake

Place the first cake layer on a serving plate and spread a generous layer of frosting on top. Repeat with the remaining layers, leaving the top and sides unfrosted for now. This creates a “naked” effect that showcases the cake’s texture.

Once all layers are stacked, use the remaining frosting to cover the top and sides of the cake. For a rustic look, leave some of the cake exposed. For a smoother finish, apply a thin crumb coat first, chill for 15 minutes, then add the final layer of frosting.

Garnish with additional key lime zest for a pop of color and extra citrus flavor. Slice and serve at room temperature for the best texture and flavor.

Essential Equipment for Perfect Results

Mixing Essentials

Start with a stand mixer—I rely on my KitchenAid 5-quart for creaming butter and sugar to perfect fluffiness. A whisk attachment works wonders for the cake batter, while the paddle attachment is ideal for frosting. This investment pays off in texture and ease. 💪

Precision Baking Tools

Accurate measurements matter, so I use OXO Good Grips measuring cups for dry ingredients and a liquid measuring cup for buttermilk and lime juice. A microplane is my go-to for zesting limes finely without any bitter pith.

Cake Pan Setup

Three 8-inch round pans with 2-inch sides ensure even baking. I swear by Fat Daddio’s anodized aluminum pans—they conduct heat evenly and release cakes cleanly. Always grease and flour them, even if they’re nonstick.

Oven Thermometer

Don’t trust your oven’s built-in temp gauge. A $10 oven thermometer from Taylor Precision hangs inside mine, confirming the 350°F setting is accurate. This prevents dry or unevenly baked layers.

Cooling Racks

Wire cooling racks allow air circulation, preventing soggy bottoms. I use stainless steel racks that fit over my countertop. Cool layers for 10 minutes in pans, then transfer to racks to cool completely before frosting.

Frosting Tools

An offset spatula makes frosting smooth and even. For piping, a large star tip creates beautiful swirls. Keep a bench scraper handy for cleaning up edges. These tools turn a homemade cake into a stunner. ✨

Frequently Asked Questions