Key Lime Pie Bars are the sunshine dessert you’ve been waiting for — tart, creamy, and perfectly portable. With zesty key lime juice and a rich, sweetened condensed milk filling on a buttery graham cracker crust, these bars capture everything delightful about a classic key lime pie but in easy, snackable squares. They’re a seasonal favorite for spring and summer cookouts but cozy enough to brighten a rainy afternoon. If you love recipes that are simple to make from scratch and reliably crowd-pleasing, this one should be on your weekend baking list — and if you enjoy hearty, from-scratch dishes, you might also like my comforting leftover turkey pot pie casserole for another homestyle twist.
Ingredients & Equipment
Ingredients
- 1 cup graham cracker crumbs
- 1/4 cup granulated sugar
- 1/2 cup unsalted butter, melted
- 1 (14 oz) can sweetened condensed milk
- 1/2 cup key lime juice (freshly squeezed is best)
- 3 large egg yolks
- 1 tablespoon lime zest (preferably from key limes if available)
- 1/4 teaspoon salt
- Whipped cream for topping
Ingredient notes
- Graham cracker crumbs: You can buy pre-crushed crumbs or pulse whole crackers in a food processor.
- Key lime juice: If you can’t find key limes, regular Persian limes work; the flavor will be slightly different but delicious.
- Sweetened condensed milk: Do not substitute evaporated milk — sweetened condensed milk gives the distinct sweet, lush texture.
- Egg yolks: Ensure eggs are at room temperature for best mixing and texture.
Equipment and helpful tools
- 8×8 inch baking dish (or an equivalent-size square pan)
- Mixing bowls (medium and large)
- Whisk and rubber spatula
- Measuring cups and spoons
- Food processor or rolling pin (for crushing graham crackers)
- Microplane or fine grater (for zesting limes)
- Oven and cooling rack
- Blender or immersion blender (optional, for an extra-smooth filling)
- Plastic wrap or airtight container for chilling and storing
Step-by-Step Instructions (with tips)
1. Preheat and prep
- Preheat the oven to 350°F (175°C). Lightly grease an 8×8 inch baking dish, or line it with parchment paper with a couple inches overhanging for easy removal of the bars.
Tip: If you like really clean edges when slicing bars, lining with parchment makes lifting the whole slab easier.
2. Make the crust
- In a medium bowl, mix graham cracker crumbs, sugar, and melted butter until combined. The mixture should hold together when pressed between your fingers.
Tip: For a nuttier crust, pulse 1/4 cup toasted pecans into the crumbs — a nod to flavors from my salted maple pecan pie bars if you enjoy a sweet-salty crunch.
3. Press into the pan
- Press the mixture firmly into the bottom of an 8×8 inch baking dish, creating an even layer. Use the bottom of a glass or measuring cup to compact it well.
Kitchen tip: Chilling the crust for 5–10 minutes before baking can help it set and reduce shrinking while baking.
4. Prepare the filling
- In another bowl, whisk together the sweetened condensed milk, key lime juice, egg yolks, lime zest, and salt until smooth. For an ultra-silky filling, pulse the ingredients briefly in a blender or use an immersion blender.
Tip: If you’re concerned about egg safety, use pasteurized eggs or gently temper the yolks by whisking a couple tablespoons of warm lime-condensed milk mixture into the yolks before combining everything.
5. Assemble
- Pour the lime mixture over the crust, smoothing the surface with a spatula.
Tip: Tap the pan gently on the counter to release any bubbles so the top bakes evenly.
6. Bake until just set
- Bake for 15–20 minutes until the filling is set but still slightly jiggly in the center. It will continue to set as it cools.
Variation: For a slightly caramelized top, you can broil for 60–90 seconds at the end — watch closely to avoid burning. Alternatively, some cooks prefer a stovetop curd for fillings; if you choose that route, gently cook the mixture (without the crust) in a double boiler until thickened, cool slightly, then pour over a pre-baked crust and chill.
Kitchen tip: Avoid overbaking — the texture should be creamy and custard-like, not dry or rubbery.
7. Cool and chill
- Allow to cool on a rack to room temperature, then refrigerate for at least 2 hours (preferably 3–4) to fully set.
Tip: Chilling overnight develops the flavor and makes slicing much neater.
8. Slice and serve
- Cut into bars and serve topped with dollops of whipped cream and a little additional lime zest or thin lime slices for garnish.
Serving tip: Run a sharp knife under hot water and wipe it dry between cuts to get clean, attractive squares.
Variations & Flavor Suggestions
- Coconut-scalloped: Fold 1/3 cup toasted shredded coconut into the crust or sprinkle on top of the whipped cream for a tropical twist.
- Graham + nut crust: Mix 2 tablespoons finely chopped toasted macadamia nuts or pecans into the graham crumbs for added texture.
- Meringue topping: Instead of whipped cream, spread a thin layer of Italian meringue and torch or broil briefly for a classic pie-inspired finish.
- Sugar swap: Use coconut sugar or a brown sugar blend in the crust for a deeper caramel note.
- Lime swap: If key lime juice isn’t available, use regular lime juice and add a teaspoon of lime zest for extra aroma.
Storage, Freezing & Make-Ahead Tips
Storing leftovers
- Refrigerator: Store bars in an airtight container for up to 4 days. For best texture, place a layer of parchment between stacked bars to prevent sticking.
- Room temperature: Don’t leave the bars out more than 2 hours if your kitchen is warm — the filling contains eggs and dairy.
Freezing
- To freeze whole: Wrap the chilled slab tightly in plastic wrap and then foil. Freeze for up to 2 months.
- To freeze individual bars: Flash-freeze bars on a baking sheet until firm (about an hour), then wrap each in plastic wrap and place in a freezer bag. This prevents sticking and allows you to pull out single servings.
Thawing
- Thaw overnight in the refrigerator. If you like the bars a touch firmer, chill for a few hours after thawing.
Make-ahead
- Crust ahead: You can prepare the crust and chill it in the pan for up to 24 hours before adding the filling and baking.
- Fully assembled ahead: Bake and chill the entire dish up to 48 hours before serving for stress-free entertaining.
Portioning advice
- Standard servings: Cut into 9 squares for generous portions, or 12–16 smaller bars for parties.
- Presentation tip: Use a fine sieve to dust a little powdered sugar or lime zest on each bar just before serving.
How to Use / Serve This Dish
- Party platter: Arrange Key Lime Pie Bars on a platter with mint sprigs and lime slices for an attractive summer dessert table.
- Coffee or tea pairing: These bright bars contrast beautifully with bold coffee or a fragrant Earl Grey tea in mid-afternoon.
- Ice cream duo: Serve a single bar alongside a scoop of vanilla bean or coconut ice cream for extra indulgence.
- Cocktail pairing: Pair with a light mojito or a gin and tonic garnished with lime for adult gatherings.
- Tiny tartlets: Press crust into mini muffin tins and bake for 8–10 minutes, then bake with smaller amounts of filling for party-friendly bite-size treats.
- Flavor balancing: Because these bars are tangy and sweet, they pair well with richer, nutty desserts — try serving a bar with a thin slice of pecan pie for complementary textures and flavors, inspired by warm, caramel-forward bakes like burnt honey pie with toffee-like flavor.
FAQ
Q: Can I substitute regular limes if I don’t have key limes?
A: Yes — regular Persian limes work fine. Key limes are more aromatic and slightly more floral, so you might notice a subtle difference, but the bars will still be bright and delicious.
Q: How long do these bars keep in the fridge?
A: Stored in an airtight container, Key Lime Pie Bars will keep for up to 4 days. The texture is best within the first 48–72 hours.
Q: Can I make these without eggs?
A: The egg yolks help provide a silky, custardy texture. If you need an egg-free version, you can experiment with a cooked lime curd thickened with cornstarch, but the texture and flavor will differ. Alternatively, use a reputable vegan condensed milk and a tested eggless filling recipe for best results.
Q: My filling curdled or looks grainy — what went wrong?
A: Overcooking or rapid temperature changes can cause curdling. To avoid this, whisk constantly if using a double boiler and remove from heat as soon as the mixture thickens. If whisking by hand, temper the yolks with a little warm mixture before combining to help stabilize them.
Conclusion
There’s something wonderfully comforting about slicing into a chilled tray of Key Lime Pie Bars: the contrast of the buttery, slightly crunchy graham crust with the tangy, silky lime filling is pure joy. Whether you make them for a summer picnic, a holiday potluck, or a quiet weekend treat, these bars are easy to scale, simple to personalize, and always a hit. If you’re looking for similar inspiration or alternate takes on key lime bars, check out this helpful roundup of other easy variations like Easy Key Lime Pie Bars from Sally’s Baking Addiction, a fresh spin from Girl Versus Dough’s Key Lime Pie Bars recipe, and another approachable version at Little Spice Jar’s Key Lime Pie Bars. Give this recipe a try — then come back and tell me how you topped yours or what creative twist you added!
Key Lime Pie Bars
Ingredients
For the crust
- 1 cup graham cracker crumbs You can buy pre-crushed crumbs or pulse whole crackers in a food processor.
- ¼ cup granulated sugar
- ½ cup unsalted butter, melted
For the filling
- 1 can (14 oz) sweetened condensed milk Do not substitute evaporated milk.
- ½ cup key lime juice Freshly squeezed is best; regular Persian limes can be used.
- 3 large egg yolks Ensure eggs are at room temperature for best mixing.
- 1 tablespoon lime zest Preferably from key limes if available.
- ¼ teaspoon salt
For serving
- Whipped cream For topping.
Instructions
Preparation
- Preheat the oven to 350°F (175°C) and lightly grease an 8x8 inch baking dish, or line with parchment paper.
- In a medium bowl, mix graham cracker crumbs, sugar, and melted butter until combined.
- Press the mixture firmly into the bottom of the baking dish to create an even layer.
- In another bowl, whisk together sweetened condensed milk, key lime juice, egg yolks, lime zest, and salt until smooth.
- Pour the lime mixture over the crust, smoothing the surface with a spatula.
Baking
- Bake for 15–20 minutes until the filling is set but still slightly jiggly in the center.
Cooling
- Allow to cool on a rack to room temperature, then refrigerate for at least 2 hours to fully set.
Serving
- Cut into bars and serve topped with dollops of whipped cream and a little additional lime zest.
