For the dough: In the bowl of a food processor, pulse together 2 cups of flour, lemon zest, orange zest, sugar, salt, and baking powder. Add the butter and pulse until the mixture resembles a coarse meal. Add the eggs, wine, and vanilla. Pulse until the mixture forms into a ball. Wrap the dough in plastic wrap and refrigerate for 30 minutes.
Cut the dough into 4 equal-sized pieces. On a lightly floured surface, roll out each piece of dough until 1/4-inch thick. Cut each piece of dough into 1/2-inch wide strips. Cut each strip of pastry into 1/2-inch pieces. Roll each piece of dough into a small ball about the size of a hazelnut. Lightly dredge the dough balls in flour, shaking off any excess. In a large heavy-bottomed saucepan, pour enough oil to fill the pan about a third of the way. Heat over medium heat until a deep-frying thermometer inserted in the oil reaches 375 degrees F. (If you don't have a thermometer a cube of bread will brown in about 3 minutes.). In batches, fry the dough until lightly golden, about 2 to 3 minutes. Transfer to a paper towel-lined plate to drain. (The rested and quartered dough can also be rolled on a floured work surface into 1/2-inch thick logs and cut into equal-sized 1/2-inch pieces. The dough pieces can then be rolled into small balls and fried as above).
In a large saucepan, combine the honey, sugar, and lemon juice over medium heat. Bring to a boil and cook, stirring occasionally, until the sugar is dissolved, about 3 minutes. Remove the pan from the heat. Add the fried dough and hazelnuts and stir until coated in the honey mixture. Allow the mixture to cool in the pan for 2 minutes.
Spray the outside of a small, straight-sided water glass with vegetable oil cooking spray and place in the center of a round platter. Using a large spoon or damp hands, arrange the struffoli and hazelnuts around the glass to form a wreath shape. Drizzle any remaining honey mixture over the struffoli. Allow to set for 2 hours (can be made 1 day in advance). Decorate with sprinkles and dust with powdered sugar, if using. Remove the glass from the center of the platter and serve.
To toast the hazelnuts, arrange in a single layer on a baking sheet. Bake in a preheated 350 degrees F oven until lightly toasted, 8 to 10 minutes. Cool completely before using.
Recipe courtesy of Giada De Laurentiis