line a 9x13 inch pan with parchment or foil and lightly grease
mix graham cracker crumbs with melted butter and sugar and salt if using until evenly moistened
press firmly into an even layer in the pan.
Layer, bake, and slice
sprinkle chocolate chips evenly over crust then add butterscotch chips if using
scatter coconut then pecans evenly over top
drizzle sweetened condensed milk slowly and evenly over all layers and lightly press to help it adhere
bake until edges are golden and center is set 25 to 30 minutes
cool completely at room temperature then chill 30 to 60 minutes for cleaner cuts
lift out and slice into bars.
Notes
1. Line the pan for easy removal; toast pecans for deeper flavor; swap pecans with walnuts or almonds; use unsweetened coconut for less sweetness; store airtight up to 5 days or freeze up to 2 months