walnut shortbread cookies 

1. Preheat oven to 325°F. Spread walnuts out on a baking sheet and bake for about 8 minutes, or until fragrant and just beginning to darken. Set aside to cool, then roughly chop to pea sized pieces.

2. In the bowl of a stand mixer fitted with a paddle attachment, cream butter, sugar, salt and vanilla on medium high speed until smooth but not fluffy, about 1 minute. Add walnuts, chocolate and flour and mix slowly just until a crumbly dough forms.

For slice and bake cookies: 

3. Shape the dough into a smooth 2-inch log and wrap in plastic wrap. Refrigerate until very firm, at least 2 hours.

4. When ready to bake, preheat oven to 350°F. Line two baking sheets with parchment paper and set aside. 

5. Use a sharp knife to slice cookies into 1/4-inch thick slices. Arrange cookies at least 1/2- inch apart on prepared pans. Bake for 13- 15 minutes, or until golden on the edges. Let cookies rest a few minutes on the sheet pan, then carefully transfer to a wire rack to cool completely. Drizzle with melted mocha chocolate and sprinkle with flaky salt.

For perfectly round roll out cookies: 

3. Turn out dough to a lightly floured work surface, divide in half, and shape into two 1-inch thick disks. Wrap in plastic and refrigerate until very firm, at least 2 hours.

4. When ready to bake, preheat oven to 350°F.

5. Place one disk between two pieces of parchment paper and roll out to 1/4-inch thick. Repeat with remaining dough. Stack slabs of dough on top of each other and chill in the freezer for 10 minutes. 

6. Cut out rounds with a 2-inch cookie cutter and transfer to a muffin tin (no need to grease the cups). Re-roll and chill scraps as needed. Store unbaked cookies on a parchment paper-lined sheet pan in the refrigerator. 

7. Bake for 13- 15 minutes, or until cookies are firm to the touch and edges are just beginning to brown. 

8. Let cool in the muffin tin for a few minutes, then use a knife or small offset spatula to carefully transfer them to a rack to cool completely. Repeat baking remaining cookies.

9. When cookies are cool, drizzle with melted mocha chocolate and sprinkle with flaky salt.