Instructions:
- Preheat the oven to 350°F (175°C) and line a 9×13-inch baking pan with parchment paper, leaving an overhang on the sides for easy removal.
- In a large bowl, cream together the softened butter and powdered sugar until light and fluffy.
- Gradually add the flour and salt to the butter mixture, mixing until fully combined and the dough starts to come together.
- Press the dough evenly into the bottom of the prepared baking pan. Use a fork to prick the dough all over.
- Bake the crust in the preheated oven for 15-20 minutes, or until lightly golden brown.
- While the crust is baking, prepare the key lime filling. In a medium bowl, whisk together the eggs, granulated sugar, key lime juice, flour, baking powder, salt, and key lime zest until smooth.
- Pour the filling over the hot crust and return the pan to the oven.
- Bake for an additional 20-25 minutes, or until the filling is set and the edges are lightly golden brown.
- Remove from the oven and let the bars cool completely in the pan on a wire rack.
- Once cooled, dust the top with powdered sugar, if desired.
- Use the parchment paper overhang to lift the bars out of the pan and transfer them to a cutting board.
- Cut into squares or bars and serve.
Enjoy these delicious key lime shortbread bars as a refreshing treat!