These double chocolate cookies with walnuts are easy. We love them with buttery walnuts, but hazelnuts or almonds would also be delicious. We use a handheld mixer — we have this one from KitchenAid, but a stand mixer works, too.
1 cup all-purpose flour
1/4 cup unsweetened cocoa powder
1/2 teaspoon baking soda
1/4 teaspoon kosher salt
8 tablespoons (1 stick) unsalted butter, at room temperature
1/2 cup granulated sugar
1/2 cup packed brown sugar
1 teaspoon vanilla extract
1 large egg, at room temperature
3/4 cup walnuts, chopped
1/2 cup chocolate chips
Heat the oven to 350 degrees F. Line two baking sheets with parchment paper or use a silicon baking mat.
Sift the flour, cocoa powder, baking soda, and salt together. Set aside.
Add the butter, both sugars, and the vanilla to a large bowl. Cream the butter and sugars together until light and fluffy; 3 to 5 minutes. (Or, use a stand mixer fitted with the paddle attachment).
Scrape the side and bottom of the bowl then add the egg. Mix on medium-low speed for 30 seconds. The egg will not be completely incorporated.
Turn the speed to the lowest setting. Add the dry ingredients in thirds, beating until just combined; 1 to 2 minutes.
With the mixer on low, add the walnuts and chocolate chips and mix until just incorporated.
Drop 1 1/2 tablespoon-mounds, or use a medium cookie scoop, onto baking sheets. Leave 2 inches between the cookies to allow for spreading. Lightly press cookie dough mounds down towards the baking sheet.
Bake the cookies, one sheet at a time, for 8 to 10 minutes. The edges should be dry and tops slightly cracked. Let the cookies cool on the baking sheet for 2 minutes then transfer to a wire rack to cool completely.
Store the cookies in an airtight container for up to 3 days at room temperature or up to a week in the refrigerator.