For the crust:
- 8 tablespoons unsalted butter (1 stick), at room temperature
- 1/4 cup sugar
- 1 cup unbleached all-purpose flour
- pinch salt
For the filling:
- 1 1/2 cups sugar
- 3 egg whites
- 1 whole egg
- 2/3 cup freshly squeezed lemon juice (from 3 lemons)
- 2 tablespoons lemon zest (from 2 lemons)
- 2/3 cup unbleached, all-purpose flour
- pinch of salt
- 1-2 cups of frozen raspberries, defrosted
- 1 tablespoon confectioner’s sugar
Preheat oven to 350 degrees. Line a 8×8″ square baking pan with a strip of parchment paper that covers the bottom and overlaps on either side (this is so after it cools, you can pull out the entire pan of lime bars and cut them neatly).
Cream butter, sugar, and salt with an electric mixer. Mix in flour until just incorporated. Flour hands and press dough into 8×8″ square baking pan, so that it comes up about a 1/2 inch around the sides.
Bake for 20-25 minutes, or until slightly golden brown. While it cools, prepare the filling.
Whisk sugar, egg whites, egg, lemon juice and zest, flour, and salt in a large bowl. Pour raspberries into a sieve and press through to extract all the pulp and juices. Discard any remaining seeds. Whisk into lemon mixture and pour into crust. Bake for 30-35 minutes until filling is completely set.
Let cool completely then place in the fridge to chill. Once chilled, using the overlapping edges of parchment paper, gently lift the dessert from the pan. Cut into 16 squares. Dust with confectioner’s sugar.