1. In a small bowl, mix warm milk with yeast and a pinch of sugar. Let stand for 5–10 minutes until foamy.

2. In a large bowl, combine flour, sugar, and salt.

3. Add yeast mixture, eggs, and butter; knead until smooth and elastic (about 10 minutes).

4. Cover the dough and let rise in a warm place until doubled in size (about 1 hour).

5. While the dough rises, prepare the pastry cream: Heat milk until warm. In a separate bowl, whisk egg yolks, sugar, and cornstarch.

6. Slowly pour warm milk into the yolk mixture, whisking constantly, then return to the saucepan.

7. Cook over medium heat until thickened. Remove from heat, stir in butter and vanilla. Cover with plastic wrap directly on the surface and cool.

8. Once dough has risen, roll out to 1/2-inch thickness and cut circles using a round cutter.

9. Place on a tray, cover, and let rise again for 30 minutes.

10. Heat oil to 350°F (175°C) and fry bomboloni in batches until golden on both sides.

11. Drain on paper towels, then roll in granulated sugar.

12. Pipe cooled pastry cream into each bombolone through the side or top.

13. Serve warm or at room temperature.