Key Lime Shortbread Bars Recipe

4.16 from 13 votes

A creamy key lime filling tops a buttery shortbread crust in these easy key lime shortbread bars.

Prep Time15

Cook Time50

Cooling Time2

Total Time3 5

Course: Sweets

Cuisine: American

Servings: bars

Calories: 312kcal

Author: Marcie

Preheat oven to 350 degrees. Line an 8x8" baking dish with parchment paper or foil.
Prepare the crust. In a large bowl, beat the butter and 1/4 cup powdered sugar till light and fluffy, about 2-3 minutes. Add flour and salt, and beat on low speed until just incorporated.
1/2 cup unsalted butter, 1/4 cup powdered sugar, 1 cup all purpose flour, 1/4 teaspoon salt
Scrape the dough into the prepared pan and spread evenly with an offset spatula. Bake on the middle rack of the oven 20-25 minutes, or until lightly golden. Remove from the oven and cool on a wire rack while you prepare the filling.
Prepare the filling. In a medium bowl, whisk the eggs and granulated sugar until well incorporated. Add the 3 tablespoons of flour and whisk until combined, then whisk in the lime juice and zest.
3 large eggs, 1 cup granulated sugar, 3 tablespoons all purpose flour, 1 tablespoon lime zest, 1/2 cup key lime juice
Pour the filling over the cooled crust, and bake 20-25 minutes longer, or until the filling has set. The filling will not "wiggle" when the pan is moved gently back and forth. Remove from heat and cool completely on a wire rack.
Once the key lime bars have cooled, cut into squares with a sharp knife, wiping the knife clean in between slices. Dust with powdered sugar, serve and enjoy!
1/2 cup sifted powdered sugar

Pro tip: Place the butter and eggs on the counter to come to room temperature up to 30 minutes in advance. Cutting the butter into small pieces and placing the eggs in warm water will speed up the process.
Cut the bars into smaller portions to serve more guests as desired.
Swap out the key lime juice for regular lime, lemon, orange and more!
Store at room temperature for up to 2 days or in the refrigerator for up to 5 days.