In a large mixing bowl, combine 1 cup of warm milk, 2 tablespoons of sugar, and 2 teaspoons of active dry yeast. Let this mixture sit for about 5-10 minutes until it becomes frothy.

Stir in 4 cups of all-purpose flour, 2 eggs, 4 tablespoons of melted butter, and 1 teaspoon of vanilla extract. Mix until a smooth, elastic dough forms, which should take about 5 minutes of kneading.

Transfer the dough to a lightly greased bowl, cover it with a clean kitchen towel, and place it in a warm area. Allow the dough to rise for 1-2 hours until it doubles in size.

Punch down the dough to release the air. On a floured surface, roll it out gently to about ½-inch thickness. Use a round cutter to cut out circles, approximately 2-3 inches in diameter.

Place the cut dough onto a floured baking sheet, cover it lightly, and let it rest for another 30 minutes to ensure they puff up a bit more.

In a deep, heavy-bottomed pan, heat vegetable oil to 350°F (175°C). Carefully drop in the rested dough circles, frying them in batches to avoid overcrowding.

Fry each bombolone for about 2-3 minutes per side or until they are beautifully golden brown. Use a slotted spoon to transfer them to a paper towel-lined plate.

Let the fried Bomboloni alla Crema cool on a wire rack for at least 10 minutes. Once cooled, prepare pastry cream or your chosen filling.

Using a piping bag fitted with a small round tip, insert the cream into the center of each doughnut, filling until just full.

Roll the filled Bomboloni in powdered sugar for a delightful finishing touch. Serve warm.