Best Key Lime Pie Bars

These Key Lime Pie Bars capture everything I love about classic key lime pie but in an easy-to-share bar form. With just nine simple ingredients and a short prep time, these are my go-to treat for picnics, potlucks, or anytime I need a zingy bite of sunshine. The balance of creamy tart filling and buttery graham crust never fails to win over a crowd.

I first tried making these bars for a last-minute barbecue and was amazed how quickly they disappeared. Now they are the most-requested dessert whenever friends come over.

Ingredients

• Graham crackers: Choose fresh crackers for a crisp crust and rich flavor
• Melted butter: Real unsalted butter gives the best taste and crumbly base
• Sweetened condensed milk: Pick quality brands for the creamiest texture and just-right sweetness
• Key lime juice: Fresh squeezed key limes bring the magical tart zing bottled juice just cannot
• Key lime zest: Adds bright aromatic lime notes Use a microplane for the finest zest
• Vanilla: Pure extract provides warm undertones that round out the citrus
• Sour cream or Greek yogurt: Lends subtle tang and makes the filling extra lush Full-fat is best
• Egg yolks: Create a smooth custardy filling with rich body and color
• Heavy cream: Cold cream whips up fluffy and sits beautifully on top
• Granulated sugar: Just enough sweetness to balance the whipping cream

Step-by-Step Instructions

Prep the Pan:

Line a square baking pan with parchment paper fitted both ways Make sure the paper comes up the sides so you can lift out the finished bars easily

Crush and Mix:

Blend graham crackers into fine crumbs then stir together with melted butter until well combined

Form the Crust:

Press crumb mixture firmly and evenly into the lined pan using a flat-bottomed cup for a solid packed crust

Blind Bake:

Bake the crust at moderate heat until golden and fragrant This helps keep the crust crisp under the creamy filling

Make the Filling:

Whisk together lime zest lime juice condensed milk vanilla and sour cream or yogurt in a bowl Start with less lime juice and condensed milk tasting and adjusting needs to be done at this stage

Incorporate Yolks:

Add egg yolks into the mixture and whisk gently to combine being careful not to overmix which could create bubbles

Assemble and Bake Again:

Pour the custard filling over the hot crust shake pan gently to settle filling and bake until edges are just set but the center is still slightly jiggly when shaken

Chill to Perfection:

Let cool at room temperature then cover and chill several hours or overnight so the filling has a chance to set into neat bars

Whip Up Topping:

Beat cold heavy cream with sugar by hand or using a mixer until stiff peaks form Spread an even thick layer over the chilled bars for that classic pie finish

Slice and Serve:

Lift bars out using excess parchment then cut into squares with a sharp knife Wipe blade between cuts for the cleanest edges

Save

The snap and zest of freshly grated key lime never gets old for me I always sneak the last sliver for myself just when the house is quiet and the whipped cream clouds are still fluffy It is the taste of sunlight in dessert form and brings back memories of summer road trips to Florida with my family

Storage Tips

Store leftover bars tightly covered in the fridge for up to four days For best texture cover only after the bars are completely cooled and set so condensation does not make the crust soggy These bars freeze well too just slice them first then wrap snugly in plastic if you want to keep a secret stash for sudden citrus cravings

Ingredient Substitutions

No key limes Use regular Persian limes for juice and zest Still delicious but with a slightly different floral note Greek yogurt can take the place of sour cream and still gives a rich tang Prefer a gluten free dessert Use gluten free graham crackers for the crust

Serving Suggestions

These bars shine chilled and cut into small squares or rectangles When serving for a party I pipe rosettes of whipped cream on top and zest a fresh lime over for a pretty pop They pair beautifully with iced tea lemonade or even a light sparkling wine for a brunch treat

Recipe Roots

Key lime pie is an iconic treat from the Florida Keys where the tiny yellow key limes grow My aunt used to make the classic pie with a meringue top but I think this bar version is even easier for gatherings The zesty flavor is the true star and the first bite always brings me back to warm island breezes

Recipe FAQs

→ Can I use regular limes instead of key limes?

Yes, regular limes work well if key limes are unavailable, though the flavor will be slightly less floral. Adjust juice to taste.

→ How do I know when the bars are done baking?

The filling should be set around the edges but slightly jiggle in the center. It will finish setting while it chills in the fridge.

→ Can I prepare these bars ahead of time?

Absolutely! They taste even better after chilling overnight and are easy to slice and serve when well chilled.

→ Is it necessary to use sour cream, or can I use yogurt?

Both sour cream and full-fat yogurt add creaminess and tang. Use whatever you prefer for the filling.

→ What's the best way to slice neat bars?

Use a sharp knife dipped in hot water and wiped dry between cuts for clean, precise slices.