These bars are gooey on the bottom and insanely crunchy on top. They blur the lines between salty and sweet — my favorite kind of snack/treat to munch on — and it's so customizable! My most recent combination was butter crackers, mini crunchy cookies and mini marshmallows.
Technique tip: Bake the bars towards the bottom of the oven so the sweetened condensed milk on top doesn't get too dark before the rest of the bars bake.
Swap options: Homemade or store-bought cookie dough (any flavor), swap any salty or sweet snacks and stud with any fun stuff in your pantry (marshmallows, chocolate, butterscotch, chips, etc). Swap sweetened condensed milk with caramel sauce or fudge sauce (it's the glue, but also informs flavor).