Preheat oven to 350°F*. Line baking pan with parchment paper (or foil) if desired**. (If using foil, spray with oil or non-stick spray.)
Add butter to a 9x13 baking pan and pop into the oven to melt butter. If using parchment paper, add butter to a medium bowl and melt in the microwave on high for 90 seconds.
Add crumbs to the pan (or bowl) and mix with butter. Press evenly on the bottom of the pan (using bottom of a measuring cup or other flat surface).
Evenly pour the sweetened condensed milk over the crust. Sprinkle with chocolate chips, coconut, then nuts. Press down firmly using a measuring cup or spoon.
Bake for 25-30 minutes, or until lightly browned. Remove pan from the oven and run a knife around the edge of the pan (if not lined). Cool completely before cutting.
Notes
*Preheat to 325°F if using a glass dish.
**Lining the pan with parchment paper allows for easy removal and cutting the squares. This is an optional step.
Store bars for 1 week in a sealed container in the refrigerator or at room temperature.
For 7 layer Magic Cookie Bars add 1 cup butterscotch chips.