In the bowl of a stand mixer fitted with the paddle attachment, beat butter and sugar at medium speed until creamy, 3 to 4 minutes, stopping to scrape sides of bowl. Add Marzipan, and beat until well combined. Beat in egg yolk and vanilla bean paste.

In a medium bowl, sift together flour and salt. With mixer on low speed, add flour mixture to butter mixture in two additions, beating until combined after each addition.

Turn out dough, and shape into a disk. Wrap in plastic wrap, and refrigerate for 30 minutes or up to overnight. (If refrigerating overnight, let dough stand at room temperature for about 15 minutes before rolling.)

Preheat oven to 325°F (170°C). Line baking sheets with parchment paper.

Between 2 sheets of parchment paper, roll dough to a ¼-inch thickness. Using a 2¼-inch thumbprint cookie stamp* dipped in flour, cut dough, rerolling scraps as necessary. Place 1 inch apart on prepared pans. Freeze until firm, about 15 minutes.

Bake until bottoms are lightly golden, 12 to 15 minutes. Let cool slightly on pans, about 5 minutes. Remove from pans, and let cool completely on wire racks. Fill centers with White Chocolate Ganache. Garnish with holiday sprinkles, if desired.