Preheat oven to 350F. Line an 8-by-8-inch baking pan with aluminum foil, spray with cooking spray; set aside.
To a large, microwave-safe bowl add the butter and heat on high power to melt, about 1 minute.
Add the graham crackers crumbs and toss lightly with a fork to coat crumbs evenly.
Turn mixture out into prepared pan, forming an even, smooth, flat crust layer by tapping crumbs into place with a spatula or your fingertips. The amount of crust is skimpy and barely covers the pan, but it’s okay.
Evenly sprinkle with the chocolate chips and butterscotch chips; set aside.
To a small saucepan, add the caramels, half-and-half, and heat over low heat to melt, whisking constantly until melted.
Add the salt, stir to combine, and taste sauce. Depending on preference for saltiness, add more salt to taste. It’s okay if the sauce reads on the salty side because many of the other ingredients in the recipe are very sweet and it balances out.
Evenly drizzle the salted caramel over the chocolate and butterscotch chips.
Evenly sprinkle the coconut.
Evenly drizzle the sweetened condensed milk over the coconut.
Bake for about 22 to 25 minutes, or until lightly golden brown around edges and the center is mostly set. Keep an extremely close eye on bars in the final minutes of baking because coconut can go from raw-looking to burnt in one minute. I’ve baked the bars in different ovens and have baked for as long as 27 minutes and as short as 20 minutes; watch your bars and not the clock.
Place pan on a wire rack and allow bars to cool in pan for at least 2 hours, or overnight, before slicing and serving. Bars firm up as they cool. Bars will keep airtight at room temperature for up to 1 week, or in the freezer for up to 6 months.