▢1 ½ sticks unsalted butter , ¾ cup, room temperature
▢1 ½ cups flour
▢⅓ cup powdered sugar
FILLING
▢3 large eggs , room temperature
▢1 ¼ cups white granulated sugar
▢¼ cup flour
▢¼ cup key lime juice , strained
▢1 teaspoon key lime zest
▢¼ teaspoon baking powder
▢⅛ teaspoon salt
Instructions
CRUST
Preheat oven to 350°F. Butter bottom and sides of an 8-inch square baking dish. Line with parchment paper with 2-inch overhang.
In a stand mixer with paddle attachment, mix butter, flour, and powdered sugar together on low speed until dough starts to form clumps.
Flour your hands to press dough into bottom and ½-inch up sides of parchment lined baking dish.
Bake in preheated oven until light golden brown, 20-22 minutes. Remove from oven and place on cooling rack.
FILLING
While crust bakes, beat eggs with an electric mixer on medium speed until light and foamy.
Add sugar, flour, key lime juice, zest, baking powder, and salt. Mix until well combined. Pour key lime mixture over crust.
Bake 22-25 minutes until edges are lightly golden and center is set.
Cool in baking dish on rack. Then chill at least 1 hour before serving. (Can be made 2 days ahead. Keep refrigerated.)
Use parchment paper overhang to remove from pan and cut into squares. Dust with powdered sugar and garnish with quartered lime wedges and additional zest, if desired.
Notes
Key lime bars will last in the fridge for 5 days. Or freeze in resealable bags up to 3 months.