Buttermilk Lime Shortbread Bars

I have made I-don't know-how-many lemon bars, but had never even thought of making lime bars until I ran across this recipe some time ago.  I always increased the amount of lemon juice in my lemon bars because I want them tart!  However, I started with the original recipe on this one only substituting this bottled lime juice or freshly-squeezed.

I gotta say, I never would have even considered using a bottled juice, but this recipe calls for 1/2 cup of juice and when I went to the grocery stores, small, hard (meaning not very juicy) limes were selling for 3 for $2.  It would have cost me a small fortune to get 1/2 cup of juice out of them.  One of the resident foodies suggested using this....not that concentrated stuff you find in the produce department.  I found it in the juice aisle and I gotta tell you, after using this, if I need more than a few teaspoons, I would definitely turn to this. 

These bars came out with just enough tartness to make your face twinge!  The zest gave it an extra depth of flavor to kind of take out a bit of the sourness.  The shortbread crust was a wonderful hardness to hold the gel.  Just be sure that the lime filling is set and doesn't jiggle when removing from the oven.  You'll want it to hold its shape.

BUTTERMILK LIME SHORTBREAD BARS (16-24 bars or so, whatever size you choose to cut the bars)

Crust:
1 1/2 cups AP flour
1/3 cup granulated sugar
1/4 tsp salt
1 tsp vanilla extract
1/2 cup (8 Tbsp) butter, cold, but into 8 pieces

Filling:
4 large eggs
1 1/3 cups granulated sugar
1/2 cup buttermilk
1/2 cup lime juice
1 Tbsp lime juice
1 tsp vanilla extract

Powdered sugar for dusting

Preheat oven to 350F.

For the crust, in a medium bowl, combine the flour, sugar, salt, and vanilla extract.  Sprinkle the butter pieces over the top of the dry mixture and using a pastry blender, two knives, or your fingers, cut the butter into the dry mixture until it resembles coarse crumbs.  Pour the mixture into the bottom of a 9x9" pan and press the crust firmly to form an even layer.  Bake the crust for 16-17 minutes, until lightly browned around the edges.

While the crust is baking, prepare the filling by whisking together all of the filling ingredients in a large bowl until evenly combined.  Pour the filling mixture over the hot crust when it comes out of the oven and return to the oven to bake for 18-20 minutes, until the filling is set (it will not jiggle if the pan is shaken slightly).

Cool the bars in the pan completely before dusting with powdered sugar, slicing, and serving.  These bars also taste excellent after they have been chilled.