Step 1: Prepare Your Pan
Preheat your oven to 350°F (175°C). Line a 9×13-inch baking pan with parchment paper, leaving overhang on the sides for easy removal later. You can also use aluminum foil sprayed with nonstick cooking spray. This step is crucial for easy cleanup and perfect bar removal!

Step 2: Make the Crust
In a medium bowl, combine the graham cracker crumbs and melted butter. Stir with a fork until the mixture resembles wet sand and all the crumbs are evenly moistened. The mixture should hold together when pressed. Pour this mixture into your prepared pan and press firmly into an even layer across the entire bottom. Use the bottom of a measuring cup or your hands to really pack it down—a firm crust prevents it from crumbling later.

Step 3: Layer the Chocolate Chips
Sprinkle the semi-sweet chocolate chips evenly over the graham cracker crust. Try to distribute them uniformly so every bar gets plenty of chocolate. Don’t press them down—just let them sit on top of the crust.

Step 4: Add the Butterscotch Chips
Sprinkle the butterscotch chips evenly over the chocolate chips. Again, distribute them evenly for consistent flavor in every bite.

Step 5: Add the Coconut
Sprinkle the shredded coconut in an even layer over the chips. The coconut will toast slightly during baking, adding wonderful flavor and texture.

Step 6: Add the Nuts
Scatter the chopped pecans or walnuts evenly over the coconut layer. If you toasted your nuts beforehand (highly recommended!), make sure they’ve cooled before adding them.

Step 7: Pour the Sweetened Condensed Milk
Here comes the magic! Open your can of sweetened condensed milk and pour it evenly over the entire surface of your layered bars. Start from one corner and drizzle back and forth, trying to cover as much surface area as possible. Use a spoon to help spread it if needed, but don’t worry about getting every single spot—the milk will spread as it bakes. The key is to distribute it relatively evenly so all areas get that wonderful gooey texture.

Step 8: Bake
Place the pan in your preheated oven and bake for 25-28 minutes, or until the top is golden brown and the edges are bubbling. The bars should look set but will still be a bit jiggly in the center—that’s perfect! They’ll firm up as they cool. Keep an eye on the coconut; if it’s browning too quickly, you can tent the pan with foil for the last 5 minutes of baking.

Step 9: Cool Completely
This is the hardest part—waiting! Remove the pan from the oven and place it on a cooling rack. Let the bars cool in the pan for at least 2 hours, or until completely cooled to room temperature. For cleaner cuts, you can refrigerate them for 1 hour after they’ve cooled to room temperature. The bars need this time to set properly; cutting them too early will result in messy, gooey pieces (though admittedly still delicious!).

Step 10: Cut and Serve
Once completely cooled, use the parchment paper overhang to lift the entire block of bars out of the pan and onto a cutting board. Use a large, sharp knife to cut into 24 squares (6 rows by 4 rows). For the cleanest cuts, wipe your knife clean between each cut. Serve and watch them disappear!