1. Combine the Parmesan cheese with the salt (and/or optional spices) and dust the counter with about one-quarter of the mixture
2. Cut the puff pastry square in half and place one half on top of the cheese, sprinkling another quarter of the cheese on top. Use a rolling pin to thin out and elongate the rectangle until it’s about ⅛" thick, continuing to sprinkle with cheese. Keep turning and rolling and moving the dough, to incorporate as much cheese as possible. Your finished rectangle should be about 6" x 15"
3. Place the dough in front of you horizontally. Fold the top edge to the center, then fold the bottom edge to the center to form a longer, skinnier rectangle. Fold both top and bottom edges toward each other as if closing a book. Repeat with second rectangle and remaining cheese mixture
4. Wrap in plastic and refrigerate the log for about 30 minutes or until firm (you can do this part ahead and freeze for several weeks – defrost on the counter for ½ hour before using)
5. Preheat oven to 425º. Place a rack in the middle of the oven
6. Using a sharp knife, cut the chilled log into ¼" thick slices and arrange cut-side-up on a parchment paper or Silpat-lined baking sheet, spaced 1" apart
7. Bake on middle rack about 8-10 minutes or until the bottoms of the palmiers are golden brown. Using a metal off-set spatula, turn the palmiers over and continue baking about 2-3 minutes longer
8. Cool completely and place in an airtight container to store for up to a week, though these are tastiest when eaten fresh!

Other Filling Ideas

• prosciutto, serrano ham, honey mustard, pesto, cheddar cheese, chili powder, Gruyere cheese, ground nuts, sun-dried tomatoes