Ina’s version combines a classic shortbread-style dough with Dutch-processed cocoa, toasted hazelnuts, and just a touch of vanilla. The result is a not-too-sweet chocolate cookie with nutty warmth and delicate crisp edges—a grown-up twist on your favorite chocolate cookie.
1 cup (2 sticks) unsalted butter, at room temperature
⅔ cup granulated sugar
1 teaspoon pure vanilla extract
1¾ cups all-purpose flour
⅓ cup Dutch-processed cocoa powder
½ teaspoon kosher salt
¾ cup toasted hazelnuts, coarsely chopped
Optional: ½ cup mini chocolate chips or chopped dark chocolate
Optional: flaky sea salt for sprinkling
Preheat oven to 350°F (175°C).
Spread hazelnuts on a baking sheet and toast for 8–10 minutes, or until lightly golden and fragrant. Rub in a kitchen towel to remove most of the skins. Chop coarsely and let cool.
In a stand mixer with the paddle attachment (or a handheld mixer), cream the butter and sugar on medium speed for 2–3 minutes until light and fluffy. Add vanilla and mix until combined.
In a separate bowl, sift together the flour, cocoa powder, and salt. Gradually add the dry ingredients to the butter mixture and mix until just combined.
Stir in chopped hazelnuts (and chocolate chips, if using) with a spatula.
Divide the dough in half. Shape each half into a log about 2 inches in diameter. Wrap tightly in plastic wrap and refrigerate for at least 1 hour, or until firm. (Dough can be chilled overnight or frozen for later.)
Preheat oven to 350°F (175°C). Line baking sheets with parchment paper.
Slice the logs into ¼-inch thick rounds and place 1 inch apart on the baking sheets. Sprinkle with flaky sea salt if desired.
Bake for 12–14 minutes, or until the edges are set and centers look slightly soft. Let cool on the pan for 5 minutes, then transfer to wire racks to cool completely.
Enjoy fresh or store in an airtight container for up to 5 days.