Panna cotta – "cooked cream" – typifies the essence of Italian cooking by elevating the clean, fresh flavor of simple ingredients – here, rich cream – without fuss or clutter. Nearly all recipes for this classic molded dessert use gelatin to set the lightly sweetened cream, resulting in an airy mousse that's a perfect foil for fresh berries or fruits. This is not that recipe. This panna cotta is an Italian flan or creme brulee, dense and creamy, each mouthful the condensed essence of fresh cream, with just enough almost-bitter caramel to cut any cloying sweetness. Instead of gelatin, this unusual recipe uses unbeaten egg whites for thickening. Unlike flan, which uses egg yolks, this panna cotta is only the palest yellow because of the butterfat in the cream. The flavor is not eggy, but rich and luxurious, almost like a full-cream cheese. Cream is the star here (there's no vanilla to overpower its delicate flavor), so if you happen to have a source for fresh heavy cream, use it. Otherwise, look for organic heavy cream with high butterfat content. You must make this recipe one day in advance of serving. The source of this recipe is as Italian as it gets: Valeria and Margherita Simili, two sisters who ran a cooking school in Bologna after growing up in the family bakery business. Promoted by Italian cooking writer Marcella Hazan at her classes, the Simili sisters specialized in classes for pasta and bread baking, but were happy to share recipes for any Italian dishes.