Step 1

Whisk flour, salt, cinnamon, and ginger in a medium bowl. Beat butter, cream cheese, and sugars with a mixer on medium speed until fluffy, about 2 minutes. Beat in yolk and walnut liqueur, then add flour mixture, beating until just combined. Form dough into a 1-inch-thick disk, wrap in plastic, and refrigerate for 1 hour.

Step 2

Using a dry pastry brush, generously dust a walnut springerle mold with confectioners' sugar. Cut a piece of dough about the size of the mold. Press dough into mold with fingers, working from center. Gently coax dough out of mold with fingertips and onto a baking sheet, and trim edges with a knife. Repeat, spacing cookies 1 inch apart on sheets and cleaning mold often. Freeze for 1 hour.

Step 3

Preheat oven to 325 degrees. Bake cookies until set, 25 to 30 minutes. Let cool on sheets on wire racks. Pipe or spread 1 teaspoon chocolate-walnut filling on flat side of 1 cookie. Press flat side of another cookie onto filling to sandwich. Repeat with remaining cookies and filling.