Sweet tart bar cookies are a vacation in a pan says Gina Neely. You can use fresh key limes or bottled. A dusting of powdered sugar, and you have the perfect dessert for any party! From Down Home with the Neely's cookbook.
Spray the bottom and sides of a 9x13 inch cake pan with nonstick spray.
Combine butter and confectioner's sugar in the bowl of an electric mixer fitted with paddle attachment. Beat on medium high for 2-3 minutes, until light and fluffy. Add flour and salt, and mix one more minute, until well combined.
Move the dough to the prepared cake pan. Pat out to an even thickness over the bottom of the pan. Bake the crust for 20-25 minutes, until lightly golden. Remove from the oven, and cool on a baking rack.
Whisk the eggs and sugar together in a large bowl. Add the flour, and whisk until just combined, then whisk in the lime juice and zest. Pour the lime topping over the cooled crust, then bake for 25 more minutes, or until filling is set.
Let the bars cool completely. Liberally dust with confectioner's sugar and cut into squares. For the neatest presentation, use a meta spatula to remove the bars from the pan.
Leftovers will keep for 2-3 days at room temperature, or for up to a week in the fridge. Enjoy!
The cookie crust dough can be prepared up to 2 days in advance, then wrapped in plastic and stored in the fridge. When you're ready to bake the bars, bring the dough to room temperature and pat out as described above.