Whisk together the cornstarch, flour, and baking powder. Set aside.

Beat the butter and sugar together until creamy (about 3 minutes)

Mix in the marzipan, egg, and vanilla extract.

Beat until the dough comes together.

Add the dry ingredients and fold them in until thoroughly combined.

Mix in the chopped rosemary.

Wrap the dough in plastic cling film and refrigerate for 1 hour

Line two baking sheets with parchment paper.

Roll out the dough on a floured surface.

Use the cookie-cutter shape of your choice to create shapes.

Transfer them to the baking sheets.

Place the baking sheets with the cutout cookies on them in the freezer for 10 minutes

Preheat the oven to 350 degrees F.

Bake for 8 minutes or until the edges of the cookies start to turn slightly golden.

Remove from oven and transfer to a baking rack to cool completely.