Dulce de leche
Some Argentinians would argue that licking dulce de leche (caramelized milk and sugar sauce) from a spoon is a meal in itself.
However, this sweet and sticky salsa usually accompanies desserts such as flan.
A better invention is dulce de leche-flavor helado.
Any ice-cream parlor that didn't stock it would soon go out of business; the bonus is that Argentinian ice-cream is thick and creamy, giving Italian gelato a decent run for its money.
For the ultimate sugar rush, DDL cones can be topped up with a little (or a lot of) DDL sauce.