In a large mixing bowl, combine the flour, sugar, yeast, and salt. Create a well in the center and add the lukewarm milk, eggs, melted butter, and vanilla extract. Stir until a dough begins to form.

Transfer the mixture to a floured surface and knead for about 8-10 minutes or until the dough is smooth and elastic.

Place the dough in a lightly greased bowl, cover with a kitchen towel, and let it rise in a warm area until it doubles in size (about 1-2 hours).

Once risen, punch down the dough and roll it out to 1/2 inch thick. Use a round cutter to cut out circles. Place them on a parchment-lined baking sheet and let rise for another 30 minutes.

In a deep pot, heat the oil over medium heat. Fry the dough circles until golden brown on both sides, about 1-2 minutes per side. Remove and let them drain on paper towels.

Once cooled, use a piping bag to fill the bomboloni with your chosen cream, filling them generously.

Finally, roll the filled bomboloni in granulated sugar for a sweet finish.