At Armando al Pantheon, a trattoria in Rome, meals often are punctuated with a slice of torta antica roma— a rustic tart inspired by the traditional Roman combination of ricotta and cherries. It’s exceptionally light, with milky-sweet ricotta balanced by tangy, brightly hued fruit preserves. The base is a tender, buttery, almost cake-like crust, and the topping is a crumby mixture of the same composition.