1. Activate the Yeast: In a large mixing bowl (or the bowl of a stand mixer), combine the warm milk, 1 teaspoon of granulated sugar, and the active dry yeast. Give it a gentle stir. Let this mixture sit for 5-10 minutes. It should become foamy and bubbly, indicating the yeast is active. If it doesn’t foam, your yeast might be old; start again with fresh yeast.

2. Mix Wet Ingredients: Add the remaining granulated sugar, eggs, and melted butter to the yeast mixture. Whisk everything together until well combined.

3. Add Dry Ingredients: Gradually add 3 1/2 cups of the all-purpose flour and the salt to the wet ingredients. If using a stand mixer, attach the dough hook. Mix on low speed until a shaggy dough forms.

4. Knead the Dough: Increase the speed to medium-low and knead for 8-10 minutes. The dough should become smooth, elastic, and pull away from the sides of the bowl. If it’s too sticky, add the remaining 1/2 cup of flour, 1 tablespoon at a time, until it reaches the right consistency. It should be soft but not overly sticky.

5. First Rise (Bulk Fermentation): Lightly grease a large bowl with a little oil. Place the dough in the bowl, turning it once to coat. Cover the bowl tightly with plastic wrap or a clean kitchen towel. Let the dough rise in a warm, draft-free place for 1.5 to 2 hours, or until it has doubled in size. This step is crucial for light, airy bomboloni.

6. Punch Down and Chill (Optional but Recommended): Gently punch down the risen dough to release the air. If you have time, cover it again and refrigerate for 30 minutes to an hour. Chilling makes the dough easier to handle and cut.

7. Roll and Cut: Lightly flour your work surface. Turn the dough out and roll it to about 1/4 to 1/3 inch thick. Use a 2.5 to 3-inch round cookie cutter (or a drinking glass) to cut out circles. Re-roll scraps gently and cut more circles until you’ve used all the dough.

8. Fill the Bomboloni: Place a small spoonful (about 1-2 teaspoons) of Nutella in the center of half of your dough circles. Be careful not to overfill, or the Nutella might seep out during frying.

9. Seal the Bomboloni: Moisten the edges of the dough circles without Nutella with a little water. Place these circles directly on top of the Nutella-filled circles. Carefully press the edges together to seal them completely, ensuring no Nutella can escape. You can also form them by placing the Nutella on one half of a circle, folding the other half over, sealing, and then using a cutter to make a perfect round again.

10. Second Rise (Proofing): Line a baking sheet with parchment paper and lightly flour it. Place the sealed bomboloni on the prepared sheet, leaving space between them. Cover loosely with plastic wrap or a clean towel. Let them rise again for 30-45 minutes, or until visibly puffy.

11. Heat the Oil: While the bomboloni are proofing, pour 6-8 cups of vegetable oil into a large, heavy-bottomed pot or Dutch oven. Heat the oil over medium heat to 350-360°F (175-182°C). Use a candy/deep-fry thermometer to monitor the temperature; maintaining it is key to perfect frying.

12. Fry the Bomboloni: Carefully transfer 2-3 bomboloni into the hot oil, being careful not to overcrowd the pot. Fry for 2-3 minutes per side, or until golden brown. They will puff up beautifully.

13. Drain and Coat: Using a slotted spoon or spider, remove the fried bomboloni from the oil. Immediately place them on a wire rack set over paper towels to drain excess oil for about 30 seconds. While still warm, roll them in a bowl of granulated sugar until fully coated.

14. Serve Warm: Enjoy your delicious, warm Nutella-Stuffed Bomboloni immediately!