Preheat the oven to 200°C / 400°F.
Roll the puff pastry into a rectangle approximately 5 mm (¼ inch) thick.
Brush the surface with beaten egg.
Mix the sugar and cinnamon together and sprinkle generously over the pastry.
Starting from one long side, roll the pastry tightly toward the center. Repeat from the opposite side so that the two rolls meet in the middle.
Cut the double roll crosswise into approximately 1 cm (⅜ inch) slices.
Gently press each slice to help form the little “ear” shape.
Arrange on a baking sheet. The vintage recipe calls for a baking sheet lightly moistened with water; parchment paper can be used for a modern kitchen.
Bake for approximately 12–15 minutes, or until puffed, crisp, and beautifully golden.
Cool slightly before serving.
