This recipe appeared on the back of Eagle Brand condensed milk cans sometime in the early 1960s, and American home bakers have been making it ever since. They go by different names depending on where you grew up: Magic Bars in the Midwest, Hello Dolly Bars in the South, Seven-Layer Bars at church potlucks from coast to coast. The recipe spread the way the best American recipes always have, passed from neighbor to neighbor, scrawled on index cards, photocopied at office parties.

What makes these bars work is the sweetened condensed milk. As it bakes, it seeps down through the layers and caramelizes against the hot pan, creating a chewy, almost candy-like base that holds everything together. The coconut toasts golden on top while the chocolate and butterscotch chips turn molten beneath. It's alchemy of the simplest kind.

I've watched students overthink this recipe. They want to know the proper technique. Here it is: dump, layer, pour, bake. That's the whole method. No mixer, no creaming butter and sugar, no tempering eggs. Just seven ingredients stacked in a pan and surrendered to the oven. The recipe practically makes itself, which is exactly why it became a fixture at every holiday cookie exchange in America.

These bars taste best the day after baking, once they've had time to set completely. They also ship well, making them ideal for care packages. I've sent them to college students, deployed servicemembers, and homesick friends who needed a taste of American comfort. They arrive intact and disappear within hours.