This key lime pound cake is a moist, citrusy Bundt cake made with almond flour, cream cheese, sour cream, and vanilla protein powder, topped with a key lime cream cheese icing. It is gluten-free, sugar-free, keto and low carb with 6.14g protein and 1.76g net carbs per slice.
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You know how it feels when you've found the holy grail of cakes? Well this is it! Super moist and just the right amount of sweet and sour makes this cake worth zesting those little tiny limes for.
You will have guests at your summer barbeque wondering what you put in this cake to make it taste so good. Get ready to soak in all the compliments, but make sure you get your piece first or it'll be gone before you know it!
I originally developed this recipe in 2021 and it was due for an update. I swapped the protein powder and added more lime flavor, plus got more gorgeous photos. This recipe is inspired by my mom's love of all things key lime. She even helped develop it! I hope you and your family will enjoy this summer treat at your next gathering.
Ingredients
Here's what you'll need to make this:
For the Pound Cake
- Almond flour - The base of the batter. Use blanched, finely ground for the best crumb. Weigh it!
- Baking powder - Gives the cake some lift. Rumford gluten-free baking powder is my go-to.
- Sea salt - Brings out the sweetness and brightens the lime flavor. I used Redmond Real Salt.
- Butter - Adds richness and helps create that dense, moist pound cake texture. Make sure it is fully softened at room temperature before mixing.
- Cream cheese - Keeps the crumb soft and adds a subtle richness without making the cake heavy. Softened at room temperature, like the butter.
- Granulated sugar-free sweetener - For sweetness. Use your preferred sweetener, but it should be erythritol-based. Allulose tends to overbrown cakes. I used Lakanto Classic.
- Vanilla extract - Rounds out the lime flavor and adds warmth.
- Key lime zest - For citrus flavor. Use about 4 key limes or 1 regular lime.
- Key lime juice - For tartness. Refrigerate your bottle as soon as you get it home, even before opening.
- Sour cream - Keeps the crumb moist and adds a subtle richness. Full fat works best.
- Eggs - Provide structure and help the batter come together smoothly. Large eggs, room temperature, added one at a time.
- Vanilla protein powder - Adds protein, helps with structure, and keeps the cake from being too dense. Milk or whey protein both work. I used Vanilla Keto Chow.
For the Icing
- Cream cheese - The base of the icing. Softened cream cheese blends smoothly without lumps.
- Butter - Adds a little richness to the glaze and helps it spread and set.
- Key lime juice + key lime zest - Both go into the glaze for bright, tart citrus flavor that stands up against the sweetener.
- Powdered sugar-free sweetener - Swerve or another powdered erythritol blend works well here. It dissolves smoothly and gives the glaze a clean finish.
- Unsweetened almond milk (or heavy cream) - Thins the icing to your preferred consistency. Add it a tablespoon at a time until you like the thickness.
See recipe card for full measurements below.
Instructions
Quick tips before you get started
- Make sure the cream cheese, butter, and eggs are all room temperature. This is very important to the success of this cake! If you are running short on time, you can always speed up the process by putting the ingredients in a freezer bag and let it sit in a bowl with warm water for about 5 minutes. The eggs should no longer be cool to the touch, and the cream cheese and butter should leave a clear indent when pressed.
- Be careful not to overmix. The eggs should be added one at a time on medium speed until you see no streaks of egg. The dry ingredients should be just barely mixed in on low speed. Then finished with a couple turns of the spatula to get the bottom.
- Generously grease your Bundt pan. I use a stick of butter to grease the pan making sure every little crevice is double covered. If you have an old rusty pan (like I did), get a new one. I recommend Nordic Ware, which is the original Bundt pan manufacturer.
- Don't overbake. Bake at 325 degrees F for 45-60 minutes until a toothpick inserted in the middle comes out clean. Tent halfway through baking to avoid overbrowning.
- Allow it enough time to cool in the pan, about 30 minutes before inverting onto a wire rack. If it sticks, set the pan in warm water to help it release.
Okay, here's how to make it:
- Preheat oven to 325 degrees F. Whisk together dry ingredients. Set aside.
- Beat the butter until creamy.
- Mix in cream cheese until smooth.
- Mix in sweetener until well combined.
- Mix in the flavoring ingredients.
- Add eggs one at a time. Do not overmix.
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- Mix in dry ingredients. Do not overmix.
- Scoop into the greased Bundt pan. Batter will be thick.
- Bake at 325 degrees F for 45-60 minutes. Allow to cool about 30 minutes in the pan, then invert onto wire rack.
- Make cream cheese icing.
Finally, pour on icing on the cooled cake, and allow it to set up. I put mine in the fridge to set up for about 15 minutes.
Slice and enjoy!
See recipe card for detailed instructions and more tips below.
Tip: A cookie scoop makes it easier to spoon the batter into the Bundt pan evenly.
Variations
- Swap in regular limes. If key limes are hard to find, regular lime juice and zest work just as well in both the batter and the icing.
- Skip the icing. The cake holds up well on its own if you want something a little lighter. A dusting of powdered sweetener is a simple alternative.
- Try a lemon version. Swap the key lime zest and juice for lemon and it becomes a whole different cake. I bet it will taste like my lemon protein bars.
Try my easy no-bake cheesecake or lemon fruit pizza next for another summer treat!
Storage
- Store leftover cake covered on the counter for 3 days, or in the refrigerator for up to 5 days. The glaze holds up fine when chilled and the cake actually gets a little moister the next day.
- To freeze, wrap individual slices tightly and freeze for up to 3 months. Let slices thaw in the refrigerator overnight, or leave at room temperature for about an hour.
FAQ
Yes. Regular lime juice and zest work in both the batter and the glaze. Key limes have a slightly more floral, tart flavor, but the difference is subtle once the cake is baked. Use whichever is easier to find.
Bundt pans need to be generously greased, especially in all the ridges. If the cake still sticks after the 30-minute rest, set the pan in a bowl of warm water for a minute or two. The gentle heat helps loosen it from the sides without breaking the cake.
Milk or whey protein both work well here because they behave similarly in baking. Keto Chow vanilla is a good option if you already use it. I used 40 grams so make sure to weigh your protein powder to get the serving size right.
The most likely culprit is overmixing after the eggs go in or after the dry ingredients are added. Mix on medium speed and stop as soon as things are incorporated. Cold ingredients can also cause the batter to seize up, so make sure everything is truly at room temperature before you start.
Related
Looking for other recipes like this? Try these:
Recipe
Keto Key Lime Pound Cake
Ingredients
Pound Cake
- 1 cup almond flour
- 2 teaspoon baking powder
- ¼ teaspoon sea salt
- ½ cup butter room temperature
- 4 oz cream cheese room temperature
- ¾ cup granulated sugar-free sweetener
- 1 teaspoon vanilla extract
- 1 tablespoon key lime zest about 4 key limes or 1 whole lime
- 1 tablespoon key lime juice
- ¼ cup sour cream
- 4 eggs room temperature
- ½ cup vanilla protein powder (40 grams)
Cream Cheese Icing
- 4 oz cream cheese room temperature
- 1 tablespoon butter room temperature
- 2 tablespoon key lime juice
- 1 tablespoon key lime zest about 4 key limes or 1 whole lime
- ½ cup powdered sugar-free sweetener
- 2-3 tablespoon unsweetened almond milk or heavy cream to thin to your desired consistency
Instructions
- Preheat oven to 325 degrees F. Generously grease a Bundt pan with butter.
- Whisk together almond flour, protein powder, baking powder, and sea salt in a small bowl. Set aside.
- Mix butter on high with electric mixer or stand mixer in a large bowl until creamy.
- Add cream cheese and mix until all lumps are gone.
- Add granulated sugar-free sweetener and mix well.
- Add vanilla extract, lime zest, lime juice, and sour cream and mix until creamy.
- Add room temperature eggs one at a time and mix well on medium speed before adding another egg to the mixture. Careful not to overmix.
- Add dry ingredients to the mixture. Blend on medium speed until just incorporated with no more streaks of flour. Careful not to overmix.
- Scoop cake mixture into well greased Bundt pan. Tap the pan on the counter several times for even distribution.
- Bake at 325 degrees F for 45-60 minutes until a toothpick inserted in the middle comes out clean.
- Cool in pan for at least 30 minutes before inverting onto cooling rack. Allow to cool completely before icing.
- Make icing: Combine icing ingredients in a large measuring cup (for easy pouring) and mix until smooth. Ice cake as desired. Tip: Add more unsweetened almond milk or heavy cream to the glaze to adjust to your desired thickness. Allow icing to set up in the fridge for 15 minutes before serving.
Mary Beth says
I only have key lime extract. How much should I use instead of lime juice and zest and keto chow?