A Better Key Lime Pie with Biscoff Cookie Crust

Name: 5-Ingredient Key Lime Pie With Biscoff Cookie Crust
Prep time: 15 min
Cook time: 35 min
Total time: 50 min
Cuisine: American
Ingredients: 2 x Biscoff cookie crust recipe (sub favorite graham cracker crust); 1 scant cup key lime juice, freshly squeezed (216g); 2 (14-ounce) cans of sweetened condensed milk (792g); 8 large egg yolks; 3 teaspoons key lime zest (4g); (optional ingredient) 2 egg whites, stiffly beaten; 1 prepared Biscoff cookie crust or graham cracker crust; 1/3 cup + 2 tablespoons key lime juice, freshly squeezed (113g); 1 (14-ounce) can of sweetened condensed milk (396g); 4 large egg yolks; 1 1/2 teaspoons key lime zest (2g); Your choice of meringue, sweetened whipped cream, etc.

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This easy Florida Key Lime Pie with Biscoff cookie crust recipe is taller, feeds a few more guests, and makes a gorgeous presentation, especially when it's topped with sweetened whipped cream and fresh key lime slices! I've been making this pie for more than 20 years now, and it's still one of our favorites!

key lime pie in springform pan on a sheet pan

florida key lime pies sliced and some juiced halves to the right lying on a cutting board

This Key lime pie recipe includes all of the usual suspects for the filling, it has a few (easy) subtle differences that elevate it from average to impressive.

If you love this bright, tart, creamy, crunchy pie as much as we do, try out this recipe and let us know if you like it. Plus, it's perfect for making mini Key lime pies, which makes everyone happy, and they freeze really well!

I almost always serve this key lime pie with strawberry coulis or quick 15-minute homemade strawberry jam sauce to drizzle over each slice. I also like to pipe it meringue on top, or add a dollop of sweetened whipped cream to individual slices, which mellows the acidity.

My Go-to Key Lime Pie Base

I have a few versions of Key lime pie (standard key lime pie, caramel key lime pie, and standard key lime pie that includes whipped egg whites folded into the batter before baking).

Each version I make, is always double the amount of filling and double the crust compared to that of a regular 9-inch Key lime pie. And it's baked in a springform pan instead of a pie plate to accommodate the extra filling and crust. But if you need less Key lime in your life, you can halve this recipe to make a standard 9-inch Key Lime Pie in a regular pie plate.

Today, I'm showing you how to make this last version with whipped egg whites folded into the batter. It's a subtle difference that makes the finished pie just the tiniest bit lighter without being a key lime mousse cake - just smooth and creamy.

Use this recipe to make easy mini key lime pies (see below) which take less time to bake.

mini key lime pies in Chengdu China made for selling in the cafe

mini key lime pie slices with a dollop of whipped cream on top and a homemade gummy heart in front of each one on the platter

closeup of key lime pie with a slice cut out

Steve's Key Lime Pie Shop, Redhook Brooklyn

If you live in the city (Manhattan), or Brooklyn you should definitely head over to Redhook to get some of Steve's key lime pie from the original location.

Back in 2009, when the below photos were taken, the 10-inch pie, which serves 8 people, cost $25. In 2022, it cost $35, and now in 2025, it costs a $45 (or you can have it shipped for the low, low price of $79).

Now, don't get me wrong, I think this pie is every bit worth the $45 bucks, because we all know how expensive living in NYC is and the cost of goods there. But when you can make homemade key lime that tastes every bit as good for a fraction of the cost, why wouldn't you?

key limes cut in half and all the juice squeezed out of them

slices of Florida key limes on a black Epicurean Cutting board

Authentic Key Lime Pie Ingredients

The filling for this pie uses the standard ingredients for an authentic Florida Key Lime Pie, which creates that unmistakable "punchy" tart and sweet flavor.

For this post, I've doubled the typical key lime pie ingredients to make it taller and serve more people. So you'll find my scaled "2x" recipe and also the standard "1x" Key lime pie ingredients in case you want to make a standard 9-inch key lime pie in a pie plate. You can find both of these versions in the recipe card below.

freshly squeezed key lime juice
sweetened condensed milk
lime zest
egg yolks
(optional) whipped egg whites from leftover yolks get gently folded into the key lime pie batter to help lighten it a bit)

How to Know When Key Lime Pie is Finished Baking -- When to Remove Key Lime Pie from the Oven

Photos of This Father's Day Key Lime Pie

I made his pie for my Dad for Father's Day (he loves key lime pie). We had a small little BBQ cookout, but by the end, it had started raining. As the weather worsened, we kind of mangled the pie when we sliced it because I was in a hurry to cut it and take a photo before it started raining even harder.

The lighting outside and inside was pretty awful to say the least, so I'll need to make the pie again and retake better photos for you guys soon. In the meantime, here are the mangled photos!

This pie looks great decorated with piped meringue or whipped cream around the edges. If you want beautifully cut slices, fill a tall glass or jug with hot water and place your knife in it.

When the blade is warm, remove it from the water, wipe it clean with a towel, and make your first slice. Dip it back into the water, wipe it clean once more, and make the second slice. I obviously did not use this trick when slicing this key lime pie pictured below!

This is the best way to guarantee a clean, beautiful slice every time (obviously I did not use this technique for any of these photos🤣). But if all you care about is eating it, don't even bother.

How to Make the Best Key Lime Pie Step-by-Step With Photos

Making key lime pie from scratch is seriously easy, even for beginner bakers as you can see here. There's no reason you shouldn't make it at home and save money!

Step 1. Preheat the oven to 350°F/176°C and prepare graham cracker or Biscoff cookie crust according to directions.

Step 2. Beat egg whites (optional step) in the bowl of a stand mixer (or using a handheld mixer or whisk) until stiff peaks form. Remove from the bowl and set aside to fold in at the end.

Stiffly beaten egg whites an optional step and ingredient to add to homemade key lime pie to make it slightly lighter but not mousse-like.

Step 3. Beat egg yolks using the whisk attachment in the same bowl of a stand mixer (or using a handheld mixer) beat the yolks until they become a pale light yellow color and make “ribbons” when you drizzle it from the beater.

Step 4. Add sweetened condensed milk to the egg yolks and beat on medium speed for approximately 3 to 4 minutes or until the mixture is well combined.

Step 5. Add lime juice and lime zest and mix until just combined (it will noticeably thicken up when the lime juice is added). Fold in the whipped egg whites (if using), Pour the filling into the prepared crust and gently lift the spring form pan half an inch or so off of the counter and let it drop back to the counter.

Do this a couple of times to help remove any air bubbles in the filling. This must be done somewhat gently to not break the cookie crust or allow crumbs to get onto the top of your filling.

Step 6. Bake for 35 minutes, turn the oven off, and leave the pie inside the oven for 15 minutes longer with the oven door closed. Remove to a wire cooling rack and allow to cool completely. Once cooled, cover the entire cake pan with plastic wrap and store it in the refrigerator to chill and set up overnight. Serve with strawberry coulis and, Enjoy!

Key Lime Substitutions (Alternative Lime Varieties to Use)

If you live in the EU, Asia, or really anywhere outside of the South (USA) it can be often difficult to source Florida Key limes.

And you may be wondering if you can substitute regular limes for key limes in key lime pie. The answer is yes! But only if you have to because the flavor will be different.

I've made it both ways, and it's still really good but I fragrant key limes whenever I can. If you find yourself without key limes here are the next best options to substitute them:

Calamansi Lime Pie: If you’re in Asia (or lucky enough to find these super delicious little limes), use baby Calamansi limes or Thai limes. These are tiny, extremely fragrant, with floral aromas, super juicy, and easy-to-squeeze limes. They're one of my favorite lime varieties, and I've even grown the calamansi lime tree for my own personal use (and they make the best Mojitos ever).
Sicilian, Spanish, or Persian green limes are imported and found in most supermarkets.
Lemon-Lime Pie: Use a 1:1 ratio of ½ fresh Persian lime juice and ½ fresh lemon juice for a citrusy twist.
Bottled Key Lime Juice Key Lime Pie: Use this as the absolute last resort. The most popular brand is Nellie & Joe’s Key West Lime juice. It doesn't taste anything like fresh key lime juice, so don't expect it of your pie, but you'll be able to say your pie is made with 100% real Florida Key limes if that's important to you. Plus, I know there are many families out there who grew up using bottled lime juice, so to them, it doesn't taste like a "real key lime pie" unless they use the bottled juice. Either way, it's up to you!

Key Lime Pie Substitutions

As mentioned above, there are many different times of limes you can use if you don't have fresh key limes available. But if you're looking for an even quicker way to get this pie made, use these suggestions below:

Substitute the homemade key lime crust (cookie crust) for one 9-inch store-bought graham cracker crust (for the 1x pie filling) and 2 ready-made crusts for the 2x pie filing.
Nellie and Joe's Key West Lime juice for freshly squeezed lime juice.

A repurposed maple syrup jar with homemade strawberry coulis in it made with fresh for a professional touch to homemade desserts.

What to Serve with Key Lime Pie

Elevate your Key Lime Pie even further by decorating the top with whipped cream, candied key lime wheels, fresh strawberries, sweetened whipped cream, or meringue.

Then, serve it with a homemade strawberry coulis (pictured above), this 15-Minute Homemade Strawberry-Blood Orange Sauce (below left), a 15-Minute Homemade Strawberry Jam Sauce (below right), or caramel sauce. It's up to you whether you serve it with anything because it's super delicious all on its own.

strawberry blood orange sauce in a Weck tulip glass canning jar

How to Make the Best Key Lime Pie Crust

Another difference in this pie is the 2-ingredient Belgian cookie crust that I use instead of a traditional graham cracker crust.

This buttery, caramelly spiced Biscoff cookie crust elevates the pie and is the perfectly spiced balance to the tart Key Lime filling.

If you prefer to use a graham cracker crust, go for it. It'll still taste amazing.

You have the option to coarsely grind the cookies (or graham crackers) for a more rustic key lime crust or finely grind them, which is more traditional. You can see what both cookie crust options look like in the photos directly below.

Biscoff cookies crumbled using a rolling pin.

Key Lime Pie FAQ's

What are Key Limes?

Key Limes are a variety of limes that come from the Florida Keys around the Key West area. They are typically smaller, more yellow, and have more seeds and a thinner rind than the typical grocery store lime variety (Persian limes). They have a higher pH than regular limes and are therefore less acidic but also have a sharper, more fragrant lime flavor.

What's the difference between a lime and a key lime?

Key limes are typically smaller, more yellow, and have more seeds than the typical grocery store lime variety (aka Persian limes). They are less tart than Persian limes but have a sharper, more fragrant lime flavor.

What makes Key Limes special?

They have a higher pH than regular limes and are, therefore, less acidic, but they also have a sharper, more fragrant lime flavor.

How long do I bake Key Lime Pie?

Bake Key Lime Pie for 35 minutes, turn the oven off, and leave the pie inside the oven for 15 minutes longer with the oven door closed. Remove to a wire cooling rack and allow to cool completely. Once cooled, cover the entire cake pan with plastic wrap and store it in the refrigerator to chill and set up overnight.

How do I know when Key Lime Pie is done?

Key Lime Pie is finished baking and ready when the top of the filling has a “skin” on it and you can touch the top of the pie without any filling sticking onto your finger. It should also only slightly jiggle when gently shaken. Lastly, it should appear to be a bit “puffy” when it's done and blonde, not browned on the top.

Can you freeze Key Lime Pie?

Yes, you can freeze key lime pie either whole or portioned into serving sizes to easily be pulled out for quick desserts or to make ahead and take to get-togethers. Wrap the pie well in sustainable plastic wrap and place in an airtight container until ready to be eaten. Thaw whole pie in the fridge overnight or individual slices on the counter until tempered and warm enough to be eaten. Not only does Key Lime Pie freeze extremely well, but it also tastes great frozen! In fact, you can bake Key Lime Pie in popsicle molds, freeze them and dip them in chocolate, caramel, or even graham cracker crumbs for Key Lime Pie on the go!

How do I keep from feeling lime zest in my Key Lime Pie?

Using a Microplane or other similar type of fine grater to grate the zest from the limes will ensure you don't feel pieces of lime zest when eating the pie. However, if you enjoy larger zest pieces, use a traditional zest peeler with small round holes.