Remove the frozen puff pastry sheet from the package and remove the paper wrapping. Thaw the sheet of puff pastry on a piece of parchment paper, at room temperature, until it unfolds easily but is still cold. Do not leave it out at room temperature for longer than 40 minutes.
Preheat the oven to 400˚F. Unfold the dough and lay it on a non-stick cutting mat or lightly floured surface. Use a pizza cutter or knife to cut it into thin strips.
Brush the puff pastry breadsticks with melted butter. Sprinkle them with grated Parmesan cheese, garlic salt, and Italian seasoning.
Twist the breadsticks before placing them on a baking sheet covered with a silicone mat or parchment paper.
Bake the crispy Italian breadsticks at 400°F for 10-12 minutes, until golden brown and crispy.