1. Preheat your oven to 350°F (175°C) and line an 8×8 inch baking pan with parchment paper for easy removal.
2. In a medium bowl, combine the flour, sugar, and salt. Stir in the melted butter until the mixture resembles coarse crumbs.
3. Press the mixture firmly into the bottom of the prepared pan to form an even layer. Bake for 10-12 minutes, or until lightly golden.
4. While the crust is baking, whisk together the sweetened condensed milk, lemon juice, and lemon zest in a separate bowl.
5. Pour the lemon mixture over the partially baked crust, spreading it evenly with a spatula.
6. Sprinkle the crushed graham crackers and chopped nuts over the top, pressing them gently into the lemon layer.
7. Return the pan to the oven and bake for an additional 15-18 minutes, or until the top is set and lightly golden.
8. Allow the bars to cool completely in the pan before slicing into squares. I find that chilling them in the refrigerator for an hour makes slicing even easier.

These steps are infused with the kind of practical guidance I learned from my family — straightforward yet attentive, ensuring each ingredient shines in its own right. As my abuela always said, “Cook with love and patience, and the food will speak for itself.”