Preheat your oven to 200 °C (390 °F).

On a lightly floured surface, roll out the puff pastry into a rectangle.

Shape the almond paste/marzipan into a log or place it in the center of the pastry. Fold or roll the pastry to encase the almond filling completely. 

Place the pastry seam‑side down on a baking sheet lined with parchment.

Brush generously with the beaten egg for a golden, glossy finish.

(Optional) Warm and brush the top with apricot jam for extra shine and sweetness. 

Sprinkle sliced or flaked almonds on top. 

Bake for approximately 25–35 minutes, or until the pastry is puffed and golden brown.

Let cool slightly before slicing and serving.