Store-bought dulce de leche (caramel sauce), to garnish
Preheat oven to 400F (190C).
Roll out puff pastry sheets to roughly 20 centimeters x 30 centimeters. Brush half of the egg wash over pastry sheets. Lay the second pastry sheet on top of first pastry sheet. Cut pastry into eight long strips. Twist each strip three times and lay on baking sheet lined with parchment. Brush with remaining egg wash. Bake for 12-15 minutes or until golden brown.
Remove from oven and brush with melted butter. Mix sugar and cinnamon in a small bowl. Dust churros with cinnamon-sugar mixture. Drizzle with dulce de leche sauce.