Preheat oven to 400°F.
Combine the brown sugar, softened butter, and cinnamon in a small bowl. Mix until well combined. Set aside.
Unroll puff pastry sheets. Using a plate as a guide, trace and cut each sheet into a circle, using a large enough plate to use up the entire puff pastry sheet. You’ll end up with three pastry rounds.
Place one pastry circle onto a parchment-lined baking sheet. Spread half of the brown sugar-cinnamon mixture on top. Top with the second pastry circle and spread with remaining brown sugar-cinnamon mixture, then top with the final pastry circle.
Place a small bowl, upside-down, in the center of the pastry to mark the middle. Starting from the edge of the bowl, slice the pastry into 16 even sections. Grasp the ends of two sections at a time and twist them twice inwards, then pinch the ends together to form a point. Repeat all the way around- you should end up with 8 points total to form a snowflake. Brush with egg.
Bake 20 minutes or until golden brown. Dust with powdered sugar before serving.
