In a large mixing bowl, combine warm milk and active dry yeast. Let the mixture sit for 5-10 minutes until frothy.

Add granulated sugar, softened butter, eggs, and half of the all-purpose flour to the mixture. Mix until combined, then gradually incorporate the remaining flour to form a soft dough.

Turn the dough onto a floured surface and knead for about 8 minutes until smooth and elastic. Place the dough in a greased bowl, turning to coat with oil.

Cover the bowl with a towel or plastic wrap and let it rise in a warm spot until doubled in size, about 1 hour.

Punch the dough down gently and roll it out on a floured surface to about 1/2-inch thickness. Use a round cutter to cut out circles and place them on a parchment-lined baking sheet.

Fill each dough circle with a spoonful of pastry cream and fold the edges over to seal tightly. Let the filled bomboloni rest for 15-20 minutes.

Heat vegetable oil to 350°F (175°C) in a deep pot. Fry the bomboloni in batches for about 2 minutes on each side until golden brown.

Dust the warm bomboloni generously with powdered sugar and serve immediately.