Just like their better known sister, the lemon bar, these cookies pack a bright tart flavor, that can be modified based on the limes that you use. The photographed version below is a mixture of Key limes, Kaffir limes and standard limes.
1/2 pound salted butter at room temperature
1/2 cup granulated sugar
2 cups all-purpose flour
6 eggs at room temperature
3 cups granulated sugar
1-2 tablespoons finely grated lime zest
1 cup freshly squeezed lime juice
1 cup all-purpose flour
Powdered Sugar for finishing
Preheat the oven to 350.
FOR THE SHORTBREAD:
Cream together butter and sugar light and fluffy. With your mixer on low, start incorporating the flour a half cup at a time. The dough will be loose and crumbly.
Lightly butter a 9 x 13 x 2-inch baking pan and line with baking parchment.
Turn out dough from the bowl into baking pan and press in dough, building up a 1/2-inch edge all around.
Chill prepared pan in freezer for 10 minutes.
Bake the shortbread for 20 minutes, until very lightly browned. Set aside while you prepare the lime curd.
FOR THE LIME CURD:
Whisk together the eggs, sugar, lime zest, lime juice, and flour.
Pour curd over the prepared shortbread and bake for 30 to 35 minutes, until the filling is set.
Let cool to slightly warm and dust with powdered sugar.
Once cooled to room temperature, apply a second layer of powdered sugar.
Lift cookies out of the baking pan using the parchment paper.
Cut into desired size squares.
Makes 24-32 bar cookies, depending on desired size.