Ghirardelli Double Chocolate Shortbread Cookies

Beat butter, sugar, and vanilla in bowl of a heavy-duty stand mixer* fitted with a paddle attachment on low speed just until blended and creamy, 3 to 5 minutes. With mixer running on low speed, gradually add flour and cocoa and beat until dough comes together, about 1 minute, stopping to scrape down sides of bowl as needed. Beat in 2 cups chocolate chips on low speed until just combined.

Divide dough in half and roll each half into a compact 2-inch-thick log (about 8 inches long). Wrap each log in parchment paper or plastic wrap, and freeze just until firm (but not frozen solid), about 25 minutes.

Preheat oven to 350 degrees F. Line 2 large rimmed baking sheets with parchment paper.

Remove cookie dough logs from freezer and unwrap. Using a sharp serrated knife and a sawing motion, cut cookie dough into 1/2-inch-thick rounds. If rounds crumble slightly, press dough back together. Place rounds on prepared baking sheets, spacing cookies about 2 inches apart.

Bake, 1 sheet at a time, in preheated oven until firm, 15 to 18 minutes. Let cool completely on baking sheets, about 20 minutes.

To decorate, place one 12-ounce package Ghirardelli semi-sweet chocolate chips in a medium microwaveable bowl. Microwave on HIGH until chocolate is melted and smooth, about 1 minute, stirring at 30-second intervals. Dip each cookie halfway into melted chocolate and place on parchment paper-lined baking sheets.

Refrigerate until chocolate has set, about 15 minutes.