Step 1: Prepare the Baking Pan

Preheat the oven to 350°F. If using a dark non-stick pan, lower the temperature slightly to 330-335°F and extend the baking time. Line a 9×13-inch, 10×15-inch, or 12×16-inch baking pan with aluminum foil and lightly spray it with non-stick cooking spray. Lining the pan helps with easy removal and cleanup.

Step 2: Make the Crust

In a stand mixer or large mixing bowl, combine butter, sugar, and salt. Mix until smooth. Add flour and beat until just combined. The mixture will be crumbly, but that is expected. If necessary, mix with hands to help incorporate the ingredients fully.

Press the mixture evenly into the bottom of the prepared pan, ensuring a uniform thickness. Bake for 10-15 minutes until the surface of the crust feels slightly dry but is not browned. This step creates a sturdy base for the filling.

Step 3: Prepare the Filling

In a large bowl, whisk together sugar, eggs, flour, lemon juice, pineapple juice, and salt until well combined.

In a blender, food processor, or Magic Bullet, puree the strawberries until smooth. The goal is to extract as much juice and flavor as possible. If the puree is too thick, strain it through a fine mesh sieve into the egg mixture, discarding any seeds or excess pulp. Whisk to fully incorporate the fruit puree into the filling.

Step 4: Bake the Bars

Pour the filling over the baked crust. Bake for 30-45 minutes, depending on the pan size. A 9×13-inch pan will need approximately 40-45 minutes, while a 12×16-inch pan requires about 30 minutes. The bars are done when the filling is fully set and does not jiggle when the pan is gently shaken.

Step 5: Cool and Serve

Let the bars cool completely at room temperature. For best results, refrigerate them for at least two hours before cutting into squares. This allows the filling to firm up and makes slicing easier. Dust with powdered sugar before serving for an extra touch of sweetness.