¾cupgranulated sugar, turbinado sugar, or demerara sugar
pinch of cinnamon
Remove puff pastry from refrigerator and allow it to come to cool room temperature, about 20-30 minutes.
Sprinkle a good handful of sugar onto your counter. Roll out puff pastry into a rectangle about ⅛ inch thick, adding more sugar on top or bottom of pastry to keep it from sticking.
Fold the pastry in half lengthwise just to mark where the middle is, and unfold. Fold each side halfway to the middle and then again to reach the middle, leaving a small gap of about ¼ inch in the middle to allow it to fold over itself (you can place a long ruler or other straight edge in the middle to make sure the gap is there). Then fold one side over the other as your final fold.
Wrap the pastry in plastic wrap and refrigerate it for about 30 minutes, no more than an hour.
Preheat the oven to 400° F. Remove pastry from the refrigerator and unwrap (it may be slightly tacky from the sugar). Slice it into ½-inch thick slices. Dip each side of each slice into more sugar and place at least 2-3 inches apart on a parchment-lined baking sheet. Bake for 20 minutes.
Carefully flip the palmier over and continue baking for 10 more minutes. Remove from the oven and allow to cool.
Palmier are best eaten the day they're made, but can be stored in an airtight container at room temperature for a few days.