01 - Preheat oven to 400°F. Line a baking sheet with parchment paper.
02 - Unroll puff pastry sheet on lightly floured surface. Brush entire surface with melted butter and sprinkle evenly with granulated sugar.
03 - Distribute chopped chocolate over pastry, leaving a 3/4-inch border along one long edge.
04 - Starting from opposite long edge, roll pastry tightly into log. Seal edge with small amount of water.
05 - Slice log into 8 equal pieces. Arrange cut side up on prepared baking sheet, leaving space between rolls for expansion.
06 - Brush tops with beaten egg. Sprinkle with sliced almonds if desired.
07 - Bake 18-20 minutes until deep golden brown and puffed. Rotating pan halfway through for even browning.
08 - Transfer to wire rack. Cool slightly. Dust with powdered sugar before serving.