As made in Naples for the Feast of San Giuseppe, these crullers are piped from a pastry bag into ring shapes. After being fried, their centers are filled with pastry cream and cherry preserves.
Put Butter And Salt into a saucepan with 1 cup water. Boil until butter dissolves. Off heat, dump in flour all at once and stir rapidly to mix. Return pan to medium-high heat and cook, still stirring rapidly, until mixture is smooth and begins to coat bottom and sides of pan. Remove pan from heat and, one at a time, add eggs and extra yolk, stirring briskly until each addition is absorbed. Let mixture cool to room temperature. Put confectioners' sugar into a brown paper bag. Heat deep-frying oil to 375F. Using 2 teaspoons, drop in nuggets of dough about the size of a small walnut. Fry a few at a time for 5-to-6 minutes each. As they cook, the zeppoli will rise to the surface, turn over when their bottom halves are golden brown, and finally rupture slightly and puff further as the interior dough expands. Remove them from the oil when golden brown, firm, and hollow inside. (Check one from the first batch, and if the interior is at all soggy, cook the rest longer.) Drain zeppoli briefly on paper towels, then toss in the bag with confectioners' sugar. Serve at once.
Tom Maresca And Diane Darrow - Prodigy Guest Chefs Cookbook