Prepare the Pan:

1. Preheat and prep: Preheat your oven to 350°F (175°C). Line a 9×13-inch baking pan with parchment paper, leaving some overhang on the sides (this makes it easy to lift the bars out later for clean cutting). Alternatively, you can grease the pan well with butter or cooking spray, but parchment is recommended for easiest removal.

Make the Crust:

2. Mix the crust: In a medium bowl, combine graham cracker crumbs, melted butter, sugar, and salt. Stir with a fork until the mixture resembles wet sand and all the crumbs are evenly moistened. The mixture should hold together when squeezed.
3. Press the crust: Pour the crumb mixture into the prepared pan. Using your hands or the bottom of a measuring cup, press the crumbs firmly and evenly into the bottom of the pan, creating a compact layer that reaches all corners. Press firmly—a well-packed crust prevents the bars from falling apart. Make sure the crust is level and even.

Layer the Ingredients:

4. Add chocolate chips: Sprinkle 1 cup of semi-sweet chocolate chips evenly over the crust. Spread them out so they cover most of the surface but don’t worry about perfection—uneven layers add to the rustic charm.
5. Add butterscotch chips: Sprinkle the butterscotch chips evenly over the chocolate chips, distributing them across the entire surface.
6. Add coconut: Scatter the shredded coconut evenly over the chips, creating a relatively uniform layer. Don’t press down—just let it sit on top naturally.
7. Add nuts: Sprinkle the chopped pecans or walnuts evenly over the coconut layer, again distributing them across the entire surface.
8. Pour condensed milk: Here’s the magic moment! Open your can of sweetened condensed milk and drizzle it evenly over the entire surface, trying to cover as much area as possible. Use a spoon to spread it if needed, but it doesn’t have to be perfect—the milk will spread during baking. Make sure to get the edges and corners. The milk will seep down through all the layers, binding everything together.
9. Top with more chocolate: Sprinkle the remaining ½ cup of chocolate chips over the top for extra chocolate appeal and a prettier presentation.

Bake:

10. Bake the bars: Place the pan in the preheated oven and bake for 25-30 minutes. The bars are done when the edges are golden brown and bubbling, the coconut is lightly toasted, and the center is set but still slightly soft. Don’t overbake—you want these to stay chewy and gooey. If the coconut or nuts start browning too quickly, tent the pan loosely with aluminum foil for the last 5-10 minutes of baking.

Cool and Cut:

11. Cool completely: Remove the pan from the oven and place it on a wire cooling rack. Let the bars cool completely in the pan—this takes at least 2 hours and preferably longer. This cooling time is crucial! The bars need to set up completely or they’ll fall apart when you try to cut them. For cleanest cuts, refrigerate for 1-2 hours or even overnight.
12. Cut into bars: Once completely cool, use the parchment paper overhang to lift the entire slab out of the pan onto a cutting board. Using a sharp knife (wipe it clean between cuts for the neatest bars), cut into 24 squares (6 rows by 4 rows). For extra clean cuts, you can chill the bars in the refrigerator for an hour before cutting, and heat your knife under hot water, wiping dry between cuts.