Preheat your oven to 160 °C (320 °F) for conventional ovens, or 140 °C (284 °F) for fan-assisted ovens. Line a baking tray with parchment paper.

Toast the almonds in a dry skillet over medium heat until fragrant, stirring often (optional).

Grind the pistachios until you have fine pistachio flour.

Mix the ground pistachios with the toasted almonds, reserving about 4 tablespoons for later.

In a large bowl, combine the marzipan, 1 egg white, 150 g of granulated sugar, and a pinch of salt. Mix well with your hands.

Add the remaining pistachio-almond mixture and knead the dough until it becomes sticky.

Roll out the dough between two sheets of parchment paper to about 1 cm thick.

Whisk the second egg white with the sifted powdered sugar to create a thick icing. Adjust consistency with lemon juice or water if needed.

Remove the top layer of parchment paper and spread 2/3 of the icing over the dough. Set the rest aside.

Cut out stars or desired shapes and place them on the prepared baking tray.

Bake the stars on the lower rack of the oven for 6-8 minutes, until the egg whites are set but not browned.

Cool the stars on the parchment paper before carefully lifting them off.

If desired, glaze the stars with the remaining egg white mixture or melted powdered sugar, and decorate with chopped pistachios.

Combine leftover dough with the reserved pistachio-almond mixture, roll out again, and repeat cutting, glazing, and baking.

Store finished Pistachio Stars in an airtight container.