Gather all your ingredients and make a volcano wheel with the flour. At the center add the sugar, salt, butter and eggs.
Start by whisking together the eggs with a fork and slowly incorporate all the ingredients.
Carry on kneading the dough with your hands until it comes together into a smooth, even ball (it should bounce back when gently pressed with a finger). Wrap the dough in cling film and leave to rest for 1 hour in the refrigerator.
Next, divide the dough into small portions (about 7–8) and roll them thinly using a pasta machine (or a rolling pin), dusting them with flour at every passage. Make sure you roll them fine enough.
Cut the strips of dough into rectangles (about 15x10cm). Cut a strip in the middle for 1.5 inch length. Use a pasta cutter to make cute fringed edges. If not, you can also use a knife.
Fill three-quarters of a deep, medium-sized skillet with sunflower oil and set it over a low-medium heat. When the oil reaches 340°F (180°C), slip in a first batch (3–4) of crostoli. Fry them until deep-golden all over, for about 30-40 seconds, flipping them half way.. Drain them with a slotted spoon and transfer to a plate lined with absorbent kitchen paper
Let the crostoli cool to room temperature, then dust with icing sugar and eat right away, or within 3 days from frying.