These are one of my favorite cookies. I made my own crumbs as suggested and mixed them in a separate bowl, pressed into a pan sprayed with Pam. As far as putting the Sweetened condensed milk on the top or the bottom, I decided to warm the can slightly in hot water to make it more liquid, then I poured half on the crumb crust and the other half over the top,
this seemed to do the trick to adhere the crust together and coat the coconut as well. I let them cool for about 30 minutes, then cut them with a pizza cutter, but did not remove them from the pan until the next day this gave them enough time to set up properly and they were easy to remove and maintained their shape.
A favorite that everyone loves. Be sure to experiment with different kinds of chips and nuts. Make sure you pour the milk over the coconut so it will not burn, not the other way around as stated in the recipe.