In the bowl of an electric mixer, beat butter with paddle attachment for approximately 3 minutes, or until creamy. Add 1/2 cup sugar and continue to beat for 1 minute. Add salt and egg yolk, beating until blended. Add flour, beating until mixture forms a dough. With mixer on lowest speed, add cream, zest, and extracts

Shape dough into a disc and wrap with plastic wrap. Refrigerate for 2 hours. Preheat oven to 350 degrees. Line a cookie sheet with parchment paper; set aside.

On a lightly floured surface, roll dough to a 1/4-inch thickness. Using a 2 1/2-inch fluted round cutter, cut dough. Place rounds approximately 1 inch apart on cookie sheet. Evenly sprinkle with remaining 1 tablespoon sugar.

Bake for 14 minutes per batch, or until edges are lightly browned. Let cool on pans for 2 minutes. Remove to wire racks to cool completely.

When cool, dip half of each cookie into melted chocolate. Evenly sprinkle nuts over chocolate. Place on parchment paper to dry for at least 1 hour.

Store in an airtight container at room temperature for up to 1 week.