Buttermilk Lime Shortbread Bars

Lemon bars are a fantastic treat when you have fresh lemons around. The best bars have lots of real lemon juice in them, after all, not just a few drops of juice or a bit of extract. The same holds true for lime bars, which are simply a variation on lemon bars that feature limes, rather than lemons. This lime bar recipe uses a lot of freshly squeezed lime juice and tempers its tartness with buttermilk, sugar, eggs and vanilla to make a delicious topping for these shortbread bars.

The base of these bars can be whipped in in just a few seconds in the food processor. In fact, the filling can also be whizzed together in just a few seconds in the food processor, so although you might invest a few minutes squeezing and zesting limes for these bars, they take almost no time to throw together. The shortbread base is made by cutting cold butter into a mixture of flour and sugar. This mixture is pressed into your pan and baked until just set, then it is topped with the lime mixture and baked a second time. The beauty of this technique is that you don’t need to wait for the crust to cool before that second baking – just pour the lime filling onto the hot crust and put it back in the oven!

The finished bars have a zesty, lime curd-like topping with a really fresh lime flavor, and a good balance between sweet and tart. The shortbread base is tender and buttery; you definitely get a nice hit of butter in every bite. Dust the tops of these bars with confectioners’ sugar before serving to dress them up a bit, or simply serve them plain. They are good both chilled and at room temperature.

Buttermilk Lime Shortbread Bars
Crust
1 1/2 cups all purpose flour
1/3 cup sugar
1/4 tsp salt
1 tsp vanilla extract
1/2 cup butter, cold

Filling
4 large eggs
1 1/3 cups sugar
1/2 cup buttermilk
1/2 cup lime juice, freshly squeezed
1 tbsp lime zest
1 tsp vanilla extract

Preheat oven to 350F. Get out a 9×9-inch baking pan (or a Baker’s Edge pan, if you have one) and set it aside.
Make the crust. In the bowl of a food processor, combine flour, sugar, salt and vanilla extract. Cut butter into chunks and add to flour mixture. Pulse until mixture forms coarse, sandy crumbs with no piece of butter larger than a small pea. This can also be done by rubbing the butter in with your fingertips. Pour sandy mixture into pan and press mixture down very firmly (with your fingers or the back of a spoon) into an even layer.
Bake for 16-19 minutes, until just lightly browned around the edges.

While crust is baking, prepare the filling by whisking together all filling ingredients in a large bowl or whizzing together in the food processor.
When the crust comes out of the oven and is still hot, pour in filling mixture.
Bake for about 20 more minutes minutes, or until filling is set and does not jiggle when the pan is gently shaken.
Cool completely before slicing.
Top slices with confectioners’ sugar to serve.

Makes about 24 bars.