Preheat the oven to 400°. Line a large baking sheet with parchment paper.
In a small bowl, combine the sugar and cinnamon until well blended.
Unfold the sheet of puff pastry and sprinkle it generously with the cinnamon sugar. With a sharp knife or a pizza wheel, cut the puff pastry into 2-inch long sticks. Spread the pastry pieces out over the baking sheet so that they have at least 1/2-inch space between them.
Bake the puffs for about 10 minutes or until puffy and golden brown. Cool on a rack.
Store the puffs for a day or two in an airtight container.