For cookie crust:
1/2 cup unsalted butter, room temp
1/4 cup confectioners' sugar
1 cup all-purpose flour
pinch of salt
For lime filling:
2 large eggs, beaten
1 cup sugar
3 tbsp all-purpose flour
1/4 cup fresh key lime juice
1 tsp grated key lime zest
Confectioners' sugar for garnish
1. Preheat oven to 350 F. Spray bottom and sides of an 8" x 8" pan with non-stick spray.
2. For the crust: combine soft butter and sugar in an electric mixer till light and fluffy. Add the flour and salt, then mix another minute till well-combined. Transfer dough to the prepared pan, and pat out to an even thickness all over the bottom of the pan. Bake the crust for 15-20 mins till lightly golden. Remove from oven and cool on baking rack.
3. For the topping: whisk together the eggs and sugar in a mixing bowl. Add the flour and whisk until combined. Then whisk in the lime juice and zest.
4. Pour the lime topping over the cooled crust, then bake for an additional 20-25 mins, until the filling is set.
5. Allow bars to cool completely. Then cut into squares and dust generously with confectioners' sugar. Luxuriate in the fresh lime fragrance wafting through your house.