Affogato

"Crafting the perfect affogato is more than meets the eye. In fact, there's more science to the dessert than most would care to acknowledge. Using gelato boosts the incredible flavor, and gives a velvety, silky smoothness ice cream just doesn't have. This is because gelato has a lower fat content, less air, and is served at a different temperature than ice cream. Translation: if you use ice cream you'll end up with something less than perfect as the hot espresso will cause the ice cream to melt faster."