Prepare the Dough: In a mixing bowl, combine the all-purpose flour, salt, and granulated sugar. Create a well in the center and pour in the warmed milk mixed with fresh yeast; let it foam for about 5 minutes. Mix in the butter and eggs, then knead until the dough is smooth, which should take about 8 minutes.

First Rise: Shape the dough into a ball and place it in a greased bowl. Cover it with a clean cloth and allow it to rise in a warm place for about 90 minutes, or until it has doubled in size.

Shape Bomboloni: Roll out the dough to about 1/2 inch thick on a lightly floured surface. Use a round cutter to cut out circles, then let them rest for a brief moment to relax the gluten.

Fry Bomboloni: Heat vegetable oil in a deep pot to 350°F (175°C). Fry the dough rounds in small batches until they are golden brown on all sides, approximately 2-3 minutes. Once done, place them on paper towels to drain excess oil.

Fill Bomboloni: Using a piping bag, carefully create a pocket in each Bombolone and fill them with your creamy custard. Finish by dusting them with powdered sugar before serving.