Key Lime Pie Bars

One bite of these creamy, tart, and perfectly sweet Key Lime Pie Bars puts me in tropical vacation mode—FAST! Since a dreamy vacation to the Keys was not in the cards this year, these bars have been in regular rotation at my house all summer. The buttery base is loaded with Ritz crackers, brown sugar, AND graham crackers for the ultimate easy crust, while the key lime filling is velvety smooth and creamy thanks to the addition of Greek yogurt. These homemade bars are like a slice of paradise– I guarantee you’ll want to make a double batch!

Key lime pie bars topped with whipped cream and lime slices.

What is Key Lime Pie?

Key lime pie is a classic American dessert made from key lime juice, sweetened condensed milk, and a crumbly cracker crust. Its origins are hotly contested; some say this deliciously tart treat originated in the kitchens of New York City, while others more widely believe it was first made in Key West, Florida, where key limes grow in abundance. No matter where it originated, my key lime pie bar recipe gives you all the flavors of this iconic dessert in an easy-to-make and portable form!

Key limes are smaller than regular limes, and their flavor is more bitter. They’re also more aromatic and have a lighter, more yellow juice than regular limes. If you can find some fresh, a thin slice will make the perfect garnish! In my recipe, I opted for regular lime juice over key lime, because it shaved about $3.00 off my total cost, and, as you know, that’s what we’re all about here in the Budget Bytes kitchen.

Here’s what you’ll need to make these homemade key lime pie bars:

Ritz Crackers: These buttery, salty crackers make the crust extra delicious.
Graham Crackers: Use whole graham crackers, rather than the pre-made boxed crumbs, to cut costs and give the crust a better texture.
Brown Sugar: Adds sweetness and helps to bind the crust together.
Butter: Use cold, unsalted butter to make the crust.
Cornstarch & Water: Helps to thicken the key lime filling without using eggs.
Lime Juice: I use regular lime juice because it’s easy to find and budget-friendly. Feel free to use key lime juice if you can! Nellie and Joe’s key lime juice is a great option if you have some extra room in your budget!
Lime: As I use regular lime juice (which is sweeter than key lime juice), the zest and juice from a fresh lime add a little extra zing.
Greek Yogurt: Adds tang and creaminess to the filling. Use full fat Greek yogurt for the best results. The yogurt also helps give it a custardy texture, so I don’t miss eggs in my version of this recipe!
Sweetened Condensed Milk: Makes this key lime pie bars recipe extra creamy and sweet.

Is Key lime pie supposed to be yellow or green?

Believe it or not, key lime pie is supposed to be yellow! Key lime juice, by nature, is a pale yellow color, meaning the filling of a traditional key lime pie will also be yellow. Green key lime pies have added food coloring or additional ingredients to achieve the green color. So don’t worry if your homemade key lime pie bars look yellow instead of green—that’s how they should be!

Storage Instructions

Keep your key lime squares in an airtight container in the refrigerator for 3-4 days. The crust may soften slightly after a few days, but they’ll still taste delicious! These bars also freeze really well. Lay them out in a single layer on a baking sheet and freeze for an hour, then transfer to a freezer-safe container for up to 3 months. Thaw in the refrigerator overnight before serving.

I know how delicious these key lime pie bars smell fresh out of the oven, and it can be tempting to cut into them right away! However, for the best results, wait until they’ve cooled and then chill in the refrigerator for 30 minutes to an hour before cutting. Use a sharp knife and cut straight down in one motion, wiping the knife clean between each slice. This will give you beautiful, clean edges and slices that hold their shape.

A key lime pie bar being sliced in half by a fork.

These creamy, tart, and perfectly sweet Key Lime Pie Bars are like a slice of paradise and couldn’t be any easier to make!

Author: Jess – Budget Bytes

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Crust Ingredients

15 ritz crackers* ($0.55)
9 sheets of Graham crackers (1 package)** ($0.74)
4 Tbsp unsalted butter ($0.49)
3 Tbsp brown sugar ($0.09)

Filling Ingredients

2 Tbsp cornstarch ($0.10)
2 Tbsp cold water ($0.00)
1 lime, zest + juice*** ($0.25)
¾ cup lime juice ($0.49)
¼ cup full fat Greek yogurt ($1.02)
2 14 oz. cans sweetened condensed milk ($4.46)

In a food processor, combine Ritz crackers, graham crackers, unsalted butter, and brown sugar.
Pulse until well-combined, but not too fine!
Press crust evenly into parchment-lined 9×13” baking dish.
Bake crust for 15 minutes at 350°F. Remove from oven and let cool.
Gather cornstarch, cold water, lime juices, lime zest, Greek yogurt, and sweetened condensed milk. Whisk cornstarch and cold water together.****
Whisk all key lime filling ingredients together in a large mixing bowl until smooth.
Pour key lime filling on top of pre-baked crust.
Bake for another 15 minutes at 350°F. Remove from oven, allowing it to cool completely.
Pop it in the fridge for 30 minutes to an hour. Then, slice bars into squares and (optional) serve with a dollop of homemade whipped cream or Cool Whip! Enjoy.

See how we calculate recipe costs here.

*About one and a half “fresh stacks” of Ritz Crackers
**One sheet of graham crackers equals 4 crackers per sheet.
***Nellie and Joe’s key lime juice is my favorite option for this recipe, but regular lime juice works just fine and is more budget-friendly. Regular lime juice is a little sweeter than key lime juice, but I found including the extra 1-2 Tbsp of juice from the fresh lime helped give it a little more tartness!
****Whisking the corn starch and cold water together before whisking all of the ingredients together is preferable to avoid lumps.

Serving: 1squareCalories: 373kcalCarbohydrates: 61gProtein: 7gFat: 12gSodium: 319mgFiber: 1g

Read our full nutrition disclaimer here.

Key lime pie bars topped with lime slices on a plate.

how to make Key Lime Pie Bars – step by step photos

Ritz crackers, brown sugar, and graham crackers in a food processor next to a small bowl of cubed butter.

In a food processor, combine 15 Ritz crackers, 9 sheets of Graham crackers, 4 Tbsp of unsalted butter, and 3 Tbsp of brown sugar.

Key lime pie bars crust mixture in a food processor.

Pulse until well combined, but not too fine!

Hands pressing down the crust for key lime pie bars into a baking dish.

Press crust evenly into parchment-lined 9×13” baking dish. Bake crust for 15 minutes at 350°F. Remove from oven and let cool.

The ingredients for key lime pie bar filling

Gather 2 Tbsp cornstarch, 2 Tbsp cold water, ¾ cup of lime juice, the additional juice and zest from 1 lime, ¼ cup of full fat Greek yogurt, and 2 14 oz. cans of sweetened condensed milk. Whisk cornstarch and cold water together.

Whisk all key lime filling ingredients together in a large mixing bowl until smooth.

Key lime pie filling being poured over the crust in a baking dish.

Pour key lime filling on top of pre-baked crust.

Key lime pie bars in a baking dish ready to be baked.

Bake for another 15 minutes at 350°F. Remove from oven, allowing it to cool completely.

Cooked key lime pie bars in a baking dish, ready to be sliced.

Pop it in the fridge for 30 minutes to an hour. Then, slice bars into squares and (optional) serve with a dollop of homemade whipped cream or Cool Whip! Enjoy.