Italian bomboloni with Nutella

DIRECTIONS

• If you’re using DRY ACTIVE YEAST, skip to instruction number 2.
  If you’re using INSTANT YEAST, put 3½ cups flour in a bowl of a stand-mixer with a dough hook attached. Add yeast and ⅓ cup sugar and mix with a spatula. Make a well in the center of the flour, add warm milk, eggs and vanilla extract and use the mixer to knead for 5 minutes on medium-low speed.
  Skip to instruction number 3.
• If you’re using DRY ACTIVE YEAST you need to proof it first. Put ½ cup warm water, the yeast and a teaspoon of sugar in a glass and stir briefly. Let the mixture sit for 5-10 minutes until it visibly foams.
  Put 3½ cups flour in a bowl of a stand-mixer with a dough hook attached. Make a well in the center of the flour, add yeast mixture, ⅓ cup sugar minute 1 teaspoon, the rest of the milk, eggs and vanilla extract and use the mixer to knead for 5 minutes on medium-low speed.
• With mixer running, add salt and then add butter spoon by spoon, waiting for the butter to incorporate, and knead for 5 minutes longer. Transfer dough to a large lightly greased bowl, cover with plastic wrap or lightly damped towel and let dough rise for 2 hours in a warm place until it doubles in volume.
• You can now cut and fry the Bomboloni, or you can store the dough overnight in the fridge and fry the next day. If you choose to keep in fridge , punch the dough to release air, knead it for a minute using your hands, and cover very tightly with plastic wrap. Store in the fridge overnight and up to 24 hours and continue the next day.
• In the meantime prepare the Nutella cream. Put butter in a stand mixer fitted with flat beater and mix for a couple of minutes, until creamy. Add Nutella and mix for another minute, then add powdered sugar and salt and mix until very smooth. Add 2 tablespoons heavy cream and mix for 2 minutes, until fluffy. If the Nutella cream is too stiff, add another tablespoon of the heavy cream and mix again. Transfer ⅓ of the cream into a pastry bag with filling piping tip (called Bismark) and the other ⅔ into a pastry bag fitted with a star piping tip. Put in the fridge until ready to use.
• Lightly flour working surface and a baking sheet. Roll dough to ¾” thickness. Using a 1.5” round cookie cutter cut circles. Gently transfer the donuts into the baking sheet. Cover with a towel and let stand for an hour until they rise.
• Line a baking sheet with a double layer of paper towel. Heat ⅓” of oil in a frying pan over medium heat to 325 degrees (check by dropping a small piece of dough into the oil. It should just gently simmer around it.) Fry Bomboloni on both sides, a few at a time, until golden-brown, about 3 minutes total. Transfer to paper towel lined baking sheet. Repeat with the rest of the dough.
• Fill bomboloni with Nutella cream. Using the star piping tip, pipe a nice tall swirl on top of each bomboloni. Sprinkle with ground hazelnuts and serve.