1 cup (2 sticks) unsalted butter, room temperature
1/2 cup confectioners sugar
2 cups all-purpose flour
Pinch of salt
Filling
6 extra-large eggs, room temperature
3 cups granulated sugar
1 cup all-purpose flour
1/2 cup freshly squeezed blood orange juice (about 3 blood oranges)
1/4 cup freshly squeezed lemon juice (about 2 lemons)
1/4 cup freshly squeeze lime juice (about 2 limes)
1 tablespoon fresh blood orange zest
Confectioners sugar, for dusting
Instructions
Crust
Preheat oven to 350 degrees Fahrenheit. Line the bottoms and sides of a 9 x 13 inch baking pan with parchment paper and set aside.
Using an electric mixer, cream butter and sugar using paddle attachment. Stir in flour and salt until just combined.
Gather dough up in a ball and with floured hands press evenly into prepared baking pan and pressing along the sides about 1/2 inch. Chill dough for about 20 minutes.
Bake crust for about 15-20 minutes until just lightly brown. Set on a wire rack to cool. Leave oven on.
Filling
Whisk eggs, sugar, flour, juice and zest until blended. Pour over crust and bake for 30-35 minutes until filling is set. Let cool at room temperature.
Lightly dust with confectioners sugar and cut into squares.