Key Lime Pie Bars

Key lime pie is a wonderful summertime dessert that I always enjoy making. Not only is it easy to put together, but the zesty and creamy filling is completely satisfying with every bite, thanks to its combination of sweet and tart flavors. These Key Lime Pie Bars are a little bit easier to make than a traditional key lime pie and are the perfect option for a summer treat when you’re entertaining.

Key lime pie is often served in a graham cracker crust. The only problem with graham cracker crusts is that they can get soggy more quickly than some other types of crust, so I opted to use a shortbread for the base of these bars instead. The buttery shortbread is made with brown sugar and cinnamon to bring in some extra flavor and contrast more with the key lime filling. The base could easily be used for other bars, too, even when you’re not baking key lime pie.

Although I made a slightly less traditional crust for this recipe, the filling is very traditional. It combines sweetened condensed milk, key lime juice and egg yolks. Key limes are smaller and more acidic than their larger counterparts, so they really deliver a tremendous amount of lime flavor. If you can find the at your local market, you’ll probably need about 12 key limes for this recipe. If you can’t find key limes, you can use regular limes and still get great results. With larger limes, you may only need 5 or 6, depending on how juicy they are. The filling will start to thicken as soon as the ingredients are combined, as the lime juice starts to “cook” the egg yolks, but the filling is baked for a few minutes to help it set up more and to actually cook the yolks.

The bars will be set when they come out of the oven, but they will continue to set up in the refrigerator. They are dense and creamy, so don’t expect them to set up quite as firmly as, for instance, pumpkin pie. This richness makes them all the more delicious, however, and they’re still firm enough to handle easily – especially with that nice shortbread as the base. I tend to cut these in more generous slices, but feel free to cut them into bite-size pieces to serve a crowd.

Key Lime Pie Bars
Crust
1 1/2 cups all purpose flour
1/2 cup brown sugar
1/4 tsp salt
1 1/2 tsp ground cinnamon
1/2 cup butter, room temperature

Filling
1 14-oz can sweetened condensed milk
1/2 cup fresh lime juice (pref. key limes)
1/2 tsp vanilla extract
4 large egg yolks

Preheat oven to 350F. Lightly grease a 9-inch square baking pan.
Make the Crust: In a large bowl, whisk together flour, brown sugar, salt and cinnamon. Add butter and blend in at low speed until the mixture resembles wet sand. Pour into prepared pan and pack into an even layer.
Bake for 15-17 minutes, until crust is firm.
Make the filling: While the crust is baking, prepare the filling by whisking all the ingredients together. When the crust comes out of the oven and is still hot, pour the filling mixture over the crust and spread into an even layer.
Bake for an additional 10-15 minutes, until the filling is completely set.
Allow bars to cool to room temperature, then refrigerate until ready to serve.

Makes 20 bars.