Preheat the oven to 375°F (190°C) and line 2 sheet pans with parchment paper. Then, whisk the egg with 1 tablespoon of water in a small bowl to make egg wash. Set aside.

Unroll one sheet of puff pastry on a clean, lightly-floured surface. Using a rolling pin, roll the sheet of puff pastry into a 10×12-inch rectangle. Then, use a pastry brush to brush the entire sheet of puff pastry with egg wash. Make sure to get the edges!

Evenly sprinkle 1/2 teaspoon of garlic powder, 1 teaspoon of rosemary, and 3/4 cup (52 grams) of parmesan over the sheet of puff pastry. Season with Kosher salt and black pepper, to taste. Gently press the cheese and spices into the puff pastry with clean hands or a rolling pin.

With the long edge facing you, cut the sheet of puff pastry into 12 one-inch strips with a pizza cutter or sharp knife. Working one at a time, grab each end of a puff pastry strip and twist the ends away from each other until it won't twist anymore. Place 6 puff pastry straws on each sheet pan a few inches apart (they will puff up quite a bit). If some of the filling spills out, just sprinkle it over the twists.

Bake for 10 minutes. If the puff pastry straws start to curl up, use oven mitts to remove the pan from the oven. Re-straighten the puff pastry straws – be careful, they'll be hot! Then, bake the puff pastry straws for another 12-15 minutes, until they're crunchy and golden-brown.

While the puff pastry straws are baking, repeat the above process with the remaining sheet of puff pastry, parmesan, and spices. You should have 24 twists total. Serve them warm or at room temperature.