Add the eggs, flour, 1 teaspoon vanilla, salt, and citrus zest to a large bowl. Mix by hand until the mixture forms a sticky dough. Form the dough into a ball. On a lightly floured surface, knead the dough ball for 2 to 3 minutes. Cut the dough into six equal-sized pieces. Roll each piece into long, thin ropes, about 1/2-inch thick. Cut off 1/4- to 1/2-inch pieces of each dough rope and roll each one into a small ball shape (don’t worry about making them perfect; imperfect shapes work perfectly fine here).
Pour enough oil into a large, heavy-bottomed sauce pan to fill it about one third of the way. Heat the oil to 350° F. Meanwhile, prepare a dish lined with paper towels to absorb excess oil. When the oil reaches the desired temperature, carefully drop in the dough balls in small batches and fry until they puff up and become golden brown on all sides. Using a metal spider, carefully remove the fried dough and transfer to the paper towel-lined dish. Continue until all dough balls are fried.
While the dough balls fry, add the honey and the remaining teaspoon of vanilla to a small saucepan set over medium heat. Stir occasionally and remove from heat once the honey reaches a syrup-like consistency, about 5 minutes.
Add the still-warm fried dough balls to a large bowl. Pour the hot honey glaze and the nonpareils into the bowl and mix until incorporated. The struffoli can be served immediately or stored in an airtight container for 2 days.