Thaw the frozen puff pastry sheets.

Sprinkle chocolate chips evenly over one sheet of puff pastry.

Place the second puff pastry sheet on top of the chocolate chip-covered sheet.

Use a rolling pin to gently roll out the pastry sheets together, making them slightly larger and pressing the chocolate chips into the pastry.

In a small bowl, whisk the egg yolk.

Brush the beaten egg yolk evenly over the top pastry sheet.

Sprinkle granulated sugar evenly over the egg-washed pastry sheet.

Using a knife or pizza cutter, cut the pastry into 12 equal strips.

Preheat oven to 200C (392F).

Place the pastry strips on a baking sheet lined with parchment paper.

Bake in the preheated oven for approximately 15 minutes, or until golden brown and puffed.

Remove from oven and let cool slightly on the baking sheet before serving.