My thumbprint-style key lime cookies feature a buttery, graham cracker crumb-based cookie with a tart key lime filling. They taste like mini key lime pies! Recipe includes a how-to video!
Why You’ll Love My Key Lime Cookies
- All the flavors of key lime pie without the wait! No waiting hours for it to firm up in the fridge.
- Can be made with bottled or fresh key lime juice. There’s no need to search high and low for real key limes if they aren’t easily accessible to you!
- Simple & fuss-free. My technique of shaping the dough BEFORE chilling means these cookies are easy to roll and hold their shape in the oven. So often thumbprint cookies will spread and lose their shape, but not these!
- Just so cute! These cookies make the perfect bite-sized dessert for summer parties or cookouts.
These cookies are based off of my popular thumbprint cookies, but today we’re using a tart key lime filling instead of jam. We’ll also incorporate some graham cracker crumbs into the cookie dough itself for even more flavor (and key lime pie vibes!).
What You Need
Most of these ingredients should be familiar to you, but I will review a few before we dig in.
- Key lime juice. It’s important to use key lime juice and not regular lime juice when making your filling, otherwise the flavor won’t be quite right. You can use fresh-squeezed or bottled juice (I like Nellie & Joe’s Key West Lime Juice!). However, for the zest you can get away with using either regular lime zest or key lime zest.
- White chocolate chips. These will help form the base for our filling. I recommend you stick with a higher quality brand (like Ghiradelli) for the best results.
- Graham cracker crumbs. These are an essential addition for a key lime feel, we’ll mix them into the cookie dough where they’ll add a subtle but present flavor.
- Sweetened condensed milk. Make sure you use sweetened condensed milk and not evaporated milk, as they will not work the same. Unfortunately they are sold right next to each other, so it can be easy to make the mistake of grabbing the wrong one. You will have some leftover condensed milk after making the filling; feel free to make dulce de leche or use it as a coffee creamer.
- Cornstarch. Cornstarch helps our cookie dough hold its thumbprint shape and prevents the cookies from spreading too much in the oven.
SAM’S TIP: Chilling the dough is important, especially if you make your key lime cookies on a hot summer day. However, make sure that you roll and indent your cookies before chilling the dough. This method prevents cracks from forming in your cookies (since the dough is more pliable!). After the cookies have baked, re-indent them with the back of a teaspoon.
Remember, this is just an overview of the ingredients I used and why. For the full recipe please scroll down to the bottom of the post!
How to Make Key Lime Cookies
- Make the dough – cream the butter and sugars together until smooth and combined, then stir in the egg yolk and vanilla. Gradually add the dry ingredients until you have a cohesive dough.
- Form the cookies – scoop and roll 2-teaspoon sized dough balls between your palms. It’s important to make sure these are smooth with no cracks, otherwise your cookies could crack in the oven! Press your thumb (or the back of a teaspoon) into each dough ball, then place in the freezer to chill.
- Bake and let cool completely before adding your filling. If the centers of your cookies puff up in the oven, use a rounded teaspoon to re-indent each cookie right after removing them from the oven. I do this with my chocolate thumbprint cookies too!
- Add the filling – Cook the white chocolate chips, condensed milk, and lime juice over low or medium-low heat until melted, then stir in the lime zest. Don’t crank up the heat, or you could end up burning your white chocolate. Spoon the filling into your cookies and let cool completely before enjoying.
SAM’S TIP: If your key lime cookies turn out dry and crumbly, there’s a pretty good chance you over-measured your flour. I have a whole post on how to measure flour, if you’ve run into this issue before I’d definitely recommend checking that out.
Frequently Asked Questions
These cookies can be kept at room temperature for up to 2 days. If you want to keep them longer than that, you will need to refrigerate them in an airtight container. Note that the filling usually stays a bit tacky even once it’s completely cooled, so these key lime cookies aren’t great for stacking.
Yes! Just make sure to store them in an airtight container with parchment paper in between the layers. I’d recommend you enjoy them within a few months for the best flavor and texture.
I use the white chocolate in this recipe to create the proper filling texture (not for the flavor). However, I don’t want to say you can’t taste it at all. It’s a very subtle taste, but if you absolutely can’t stand white chocolate, you might not be a fan of this recipe.
Several readers have tried substituting the lime juice/zest with lemon with great success! 🍋
If you’re looking for more fun twists on classic key lime (or more ways to use up a bottle of key lime juice), check out my key lime pie cake or key lime cheesecake next.
Enjoy!
Let’s bake together! Subscribe to my newsletter to be notified of all the newest recipes, and find my free recipe tutorials on YouTube 💜
Key Lime Cookies
Ingredients
Cookies
- 1 cup unsalted butter softened
- ⅓ cup (70 g) sugar
- ⅓ cup (67 g) light brown sugar tightly packed
- 1 large egg yolk
- 1 teaspoon vanilla extract
- 2 cups (250 g) all-purpose flour
- ½ cup (65 g) graham cracker crumbs
- 2 teaspoons cornstarch
- ½ teaspoon salt
Key Lime Filling
- 1 cup (170 g) good quality white chocolate chips
- ½ cup (170 g) sweetened condensed milk
- 3 Tablespoons key lime juice
- 2 teaspoons lime zest key limes are expensive, I just used zest from a regular lime
Instructions
- Combine butter and sugars in the bowl of a stand mixer (or use a large bowl and an electric hand mixer) and beat until well-creamed.1 cup unsalted butter, ⅓ cup (70 g) sugar, ⅓ cup (67 g) light brown sugar
- With mixer on low, stir in egg yolk and vanilla extract, pausing to scrape down the sides and mixing until ingredients are well-combined.1 large egg yolk, 1 teaspoon vanilla extract
- In a separate bowl, whisk together flour, graham cracker crumbs, cornstarch, and salt.2 cups (250 g) all-purpose flour, ½ cup (65 g) graham cracker crumbs, 2 teaspoons cornstarch, ½ teaspoon salt
- Gradually add the flour mixture to your wet ingredients, being sure to scrape the sides and bottom of the bowl so that all ingredients are well-combined.
- Scoop cookie dough into 2-teaspoon-sized balls and roll until smooth (so that the dough is round and there are no cracks/seams in the cookie dough — this will help keep your thumbprints from cracking).
- Use your thumb or the rounded back of a teaspoon to gently press an indent in the center of the cookie dough. Repeat until all of the dough has been used.
- Chill imprinted dough in freezer for 30 minutes.
- Preheat oven to 350F (175C) and line cookie sheets with parchment paper (if using. An ungreased, non-stick cookie sheet will also work).
- Place chilled cookie dough on sheet spacing at least 1″ apart.
- Bake on 350F (175C) for 10-11 minutes and allow to cool completely on pan. Wait for cookies to cool completely before preparing filling.
Key Lime Filling
- In a small saucepan over medium-low heat, combine white chocolate chips, condensed milk, and key lime juice.1 cup (170 g) good quality white chocolate chips, ½ cup (170 g) sweetened condensed milk, 3 Tablespoons key lime juice
- Stir frequently until chocolate is melted and ingredients are well-combined. Stir in lime zest and stir until mixture just begins to bubble.2 teaspoons lime zest
- Reduce heat to low and spoon filling into thumbprints of cookies (I use a 1-tsp sized cookie scoop, it makes the process much easier and less messy!).
- Allow to cool completely before serving (filling may still be a little tacky to touch, even when cooled completely. This is normal).
Nutrition
Nutritional information is based on third-party calculations and should be considered an estimate only. Actual nutritional content will vary based upon brands used, measuring methods, cooking method, portion sizes, and more.
This key lime cookie recipe was originally published 06/06/2018, post updated 05/13/2019
Sally
I just got done making these. I followed the recipe exactly, except I couldn’t find key lime juice (or key limes) so I had to substitute the juice for regular lime juice and the lemon juice for the zest. They still turned out pretty good! Very unique Nd delicious! Thanks so much for this recipe 🙂
Sugar Spun Run
I am so glad that you enjoyed the key lime pie cookies, Sally! Thanks for trying my recipe and for commenting. 🙂
Susan McNamee
I make cookies for Christmas giving and these sound perfect. Can I make these ahead of time and freeze? I just discovered your website and I can’t wait to try many more of your goodies!
Sam
Hi Susan! I think they should hold up just fine in the freezer. I hope everyone loves the cookies. 🙂
Al Force
It’s just a shame that websites like this exist. I’m looking for a recipe but I have to read through your literal life story first? Who cares?
Sam
Maybe buy a cookbook instead? Maybe just don’t visit “websites like this”? I spend a lot of my time and money to develop these recipes and share them FOR FREE online and even provide a “jump to recipe” button at the top of the post so you literally don’t have to read a thing. And yet here you are, commenting and complaining, even though your time is so valuable you can’t even manage to scroll. The entitlement is real. Enjoy your free recipe.
Liz
👍🏻👍🏻👍🏻Key Lime is my favorite as was your reply!
Kathleen K Mucha
Seriously! WTF? Thank you VERY much for your time and your free recipes! Some people just aren’t happy unless they have something to b**** about, so they go out of their way to find something! Thanks again!
Sam
I am so glad you are enjoying the recipes, Kathleen! <3
Maddie
I am sorry that some people are like that Sam. I love your recipes and also to learn from you and your experience !
Sugar Spun Run
Thank you so much, Maddie! I appreciate your support. 🙂
Corrin
Eglerio anin mastor! (Elvish for ‘praise the cook’!) These are amazing! They disappeared in two days! TWO DAYS!
Absolutely wonderful. Keep up the wonderful work! 😉
Sam
Thank you so much for commenting, I’m so glad to hear they were such a hit!! 🙂
Tabitha Camacho
Incredibly unusual, but oh so good! The cookies were scarfed down so fast (work, neighbors, small group) I had to hide a few cookies just so my hubby could taste them when he got back from D.C.! I did cheat a little and used true lime for the zest and equal parts lemon w/lime juice for the key lime flavor ~ it’s what I had in my kitchen at 2200 when I made them! I will make with key lime next time to see what the difference may be (nothing is more irritating when someone says I substituted this and that and now they are good/bad – you have to make exactly as the recipe calls first, and then tweak) but honestly I will make again (and again and again) even with the subs I used, they are that tasty. The cookies are so cute and light and airy – not heavy. Mahalo!! Oh and congrats on your new house!
Sam
I’m so happy to hear the cookies were such a hit, and I do appreciate you sharing your variations! Thank you for commenting, Tabitha 🙂
anna
I so enjoy your site and your recipes. I am going to try this! Thank you. for sharing
Sam
Thank you so much, Anna! I am glad you are enjoying everything! 🙂
Sharon
Mmmmmm!
Joy
This looks incredible! I love desserts and am already drooling at this one. Surely trying this one out.
Thank you!
Sam
I hope you love it, Joy! 🙂
Corrin
Aww! These look so cute! 🙂 I hope you have a smooth time moving into your new house!
Sam
Thank you so much, Corrin! It’s certainly been rough at times but we are getting close to being done. 🙂
Barbara Evans
So far everything and I mean everything I have tried that you posted has been wonderful, I know I’ve said it before but I want to encourage you to continue on with your mission of teaching a old woman who thought she knew a lot in the kitchen new ideas.
When I was your age I could barely boil water and in my case I’m sure I scorch that.
Good site to check into for young or old cooks.
Sam
Thank you so much, Barbara! I am so glad you are enjoying everything. 🙂
Dave
I Love Key Lime Pie and cookies!!!!!! These turned out great!!!!! Thank you for posting the recipe!!!!
Sam
I am so glad you enjoyed the cookies, Dave! 🙂
Dave
Sam,
Made another batch yesterday!!!! I put a homemade whipped topping on them that took it to another level!! (Heavy Whipping Cream, white chocolate instant pudding mix, vanilla, powdered sugar, and key lime zest). Made a nice balance between cookie, tart, and sweet!!!! I really enjoy your recipes!!! Great Cookies!!!!!
Sam
That sounds amazing, Dave! That sounds like a wonderful combination. 🙂
Lynn
Dave, how did you make the whipped topping? I plan on making these for a Friendsgiving Saturday. Thank!
Amanda Jacobson
I am going to try to make these for Christmas. They sound so yummy. I hope they turn out.
Sam
I hope you love them! Let me know how they turn out. 🙂
Sandy
We’re having a Cookie Bake off and I’m going to make your cookies wish me luck. The winner gets a $50 gift card. I wanted to do something different than Chocolate chip cookies or sugar I found yours. And it sounds yummy.
Sam
I hope you win too! I have a feeling you certainly will, but let me know! 🙂
GLPMNG
I made these cookies today and they are out of this world delicious! I went a little heavier on the lime and did forget to chill them, but they turned out perfectly! Thank you for this recipe!!!
Sam
I am so glad you enjoyed the cookies! 🙂
SUSAN
I AM ABOUT TO MAKE THESE COOKIES AND WHEN I LOOKED AT THE INGREDENANTS IT SAYED I NEEDED BROWN SUGAR BUT THEN YOU LOOK AT THE COOKIE RESIPE IT NEVER SAYS ANY THIN ABOUT BROWN SUGAR
Sam
Hi, Susan. Sorry for the typo. It should be “combine butter and sugars” in the first step. I will fix that right now. 🙂
Mikaru86
Those look very interesting. I had some issues with the last thumbprint cookies while molding the dough into shape (it was too dry and brittle), so I’ll have to try these for comparison some time.
As a suggestion for anyone over here in Europe that has trouble finding graham crackers, I have always substituted them with Butterkekse (the most famous name brand here in Germany being Leibniz, but there are many functionally identical store brand alternatives): https://i.imgur.com/8rFBmFe.jpg