These key lime pie bars are a bright, refreshing dessert that pairs tangy key lime filling with a sweet, buttery cookie crust. The recipe is straightforward and uses just a few pantry staples, making it approachable for bakers of any skill level. In under an hour (plus chilling time) you can have a tray of zesty bars ready to slice and serve.
These bars are ideal for warm weather—spring and summer especially—when you want a light, citrus-forward dessert. The smooth, creamy lime filling contrasts beautifully with a crumbly graham cracker or cookie crust. Finish the bars with a sprinkle of lime zest, a few fresh lime slices, or a dollop of whipped cream to enhance the flavor and presentation.
Why You’ll Love This Recipe
- Bright, zesty key lime flavor that is both tart and sweet.
- Creamy, melt-in-your-mouth filling balanced by a crisp, chewy cookie crust.
- Simple ingredient list and quick assembly—filling is made from just sweetened condensed milk, key lime juice, and Greek yogurt.
- Perfect chilled dessert for warm days, backyard gatherings, and potlucks.
- Flexible toppings and crusts: add whipped cream, meringue, berries, or swap the crust cookie to change the flavor profile.
- Easy to adapt for dietary needs: use coconut-based sweetened condensed milk and dairy-free yogurt for a dairy-free version, and choose gluten-free cookies for a gluten-free crust.
Ingredients
- Sweetened condensed milk
- Plain Greek yogurt (or sour cream)
- Key lime juice
- Lime zest
- Graham cracker crumbs (or substitute crushed cookies like gingersnaps)
- Brown sugar
- Salted butter, melted
See the recipe card below for exact measurements.
Substitutions
If you need to adjust the recipe for dietary preferences or availability, try these simple swaps:
- Dairy-free: Use coconut sweetened condensed milk and a dairy-free yogurt. Replace butter with vegan butter or coconut oil and top with dairy-free whipped cream.
- Gluten-free: Substitute the cookie crumbs with certified gluten-free graham crackers or other gluten-free cookies.
Variations
Customize the bars by changing the crust or adding mix-ins and toppings:
- Coconut: Stir shredded coconut into the crust and sprinkle toasted coconut on top for a tropical touch.
- Ginger: Use crushed gingersnaps for a warm, spicy crust that pairs well with citrus.
- Chocolate: Replace the graham crumbs with crushed chocolate wafers for a chocolate-lime combination.
- Raspberry: Add a thin layer of raspberry jam or scatter fresh raspberries over the chilled bars for a fruity contrast.
Note: If you make substitutions, results may vary. Adjust baking times and proportions as needed.
How To Make Key Lime Pie Bars
Step 1: Combine cookie crumbs, brown sugar, and melted butter in a bowl until the mixture resembles wet sand.
Step 2: Press the crust evenly into an 8×8″ baking dish lined with parchment. Bake briefly, then let cool.
Step 3: In a separate bowl, whisk together sweetened condensed milk, Greek yogurt (or sour cream), and key lime juice until smooth and well combined.
Step 4: Pour the filling over the cooled crust and spread into an even layer.
Step 5: Bake the filled pan until the filling is set but still slightly wobbly in the center, then remove and cool to room temperature.
Step 6: Chill the bars in the refrigerator for at least 2 hours (or overnight) before slicing. Garnish with lime zest and serve with whipped cream if desired.
Baking Tips
- Use the bottom of a glass or a measuring cup to press the crust firmly and evenly into the pan.
- If you don’t have an 8×8″ pan, two standard loaf pans can work, though thickness and baking time may vary.
- A 9×9″ pan is not recommended—the crust will be thinner and the texture will change.
- Avoid overbaking the filling to prevent cracking or drying; it should set but remain creamy.
- Cool to room temperature before refrigerating to help the bars finish setting without extra condensation.
- To speed chilling, place the cooled pan in the freezer for 30 minutes, then transfer to the fridge if needed.
Frequently Asked Questions
Answers to common questions about this recipe:
Traditional recipes use sweetened condensed milk and often dairy-based toppings, but this recipe can be made dairy-free by using coconut sweetened condensed milk and dairy-free yogurt and toppings.
The standard crust uses graham crackers (which usually contain gluten), but substituting gluten-free cookies or graham crackers makes the bars gluten-free.
Properly stored in the refrigerator, they keep up to 5 days in an airtight container. They’re best within the first three days.
Yes, regular limes can be used, though key limes have a slightly different, more floral flavor. Store-bought key lime juice is a convenient alternative if fresh key limes aren’t available; this recipe requires a substantial amount of juice.
Equipment
No special tools required—just an 8×8″ baking dish, parchment paper, mixing bowls, measuring tools, a whisk, and a spatula.
Storage
Refrigerated
Store cooled bars in an airtight container or tightly covered baking dish in the refrigerator. They stay fresh for several days.
Freezing Instructions
Freeze fully cooled bars in an airtight container for up to 2 months. Thaw in the refrigerator for several hours or at room temperature for about 30 minutes before serving. Re-top with whipped cream after thawing, if desired.
More Recipes You’ll Love
If you enjoy citrus desserts, try other seasonal bakes and cookies for more bright, flavorful treats.
Recipe
Key Lime Pie Bars
- Prep Time: 20 minutes
- Cook Time: 20 minutes
- Total Time: 40 minutes (plus chilling)
- Yield: 8–12 bars
- Category: Dessert, Pies, Bars
- Method: Bake
- Cuisine: American
Ingredients
- 28 oz sweetened condensed milk
- ½ cup plain Greek yogurt (or sour cream)
- ¾ cup key lime juice
- 1 ¾ cups graham cracker crumbs (or crushed gingersnaps)
- 2 tablespoons brown sugar
- 6 tablespoons salted butter, melted
- Lime zest, for topping
Instructions
- Preheat oven to 350°F (176°C). Line an 8×8″ baking dish with parchment paper.
- Mix graham cracker crumbs, brown sugar, and melted butter until combined.
- Press mixture into the bottom of the prepared dish and bake 8–10 minutes. Cool.
- Whisk together sweetened condensed milk, Greek yogurt (or sour cream), and key lime juice until smooth.
- Pour filling over the cooled crust and spread evenly.
- Bake for 10–12 minutes until the filling is set but still slightly wobbly in the center.
- Cool to room temperature, then chill in the refrigerator for at least 2 hours or overnight.
- Slice into 8–12 bars, garnish with lime zest, and serve with whipped cream if desired.
Notes
- If the crust feels too dry to press, add an extra tablespoon of melted butter.
- For dairy-free bars, use coconut condensed milk, dairy-free yogurt, and vegan butter.
- For gluten-free bars, use gluten-free cookie crumbs for the crust.