3/4 teaspoon baking soda
1 teaspoon kosher salt
5 ounces 55 percent chocolate, cut into chip-sized pieces
5 ounces 70 to 72 percent chocolate, cut into chip-sized pieces
8 ounces (2 sticks) cold unsalted butter, cut into small pieces
1 cup packed dark brown sugar, preferably molasses sugar
3/4 cup granulated sugar
2 large eggs
Position racks in the lower and upper thirds of the oven and preheat oven to 350 degrees. Line two baking sheets with Silpats or parchment paper.
Sift flour and baking soda into a medium bowl. Stir in the salt.
Put chips in a fine-mesh basket strainer and shake to remove any chocolate “dust” (small fragments).
In the bowl of a stand mixer fitted with the paddle, beat half the butter on medium speed until fairly smooth. Add both sugars and the remaining butter, and beat until well combined, then beat for a few minutes, until mixture is light and creamy. Scrape down sides of the bowl. Add eggs one at a time, beating until the first one is incorporated before adding the next and scraping the bowl as necessary. Add dry ingredients and mix on low speed to combine. Mix in chocolate.
Remove bowl from mixer and fold dough with a spatula to be sure the chocolate is evenly incorporated.
The dough or shaped cookies can be refrigerated, well wrapped, for up to 5 days or frozen for 2 weeks. Freeze shaped cookies on the baking sheets until firm, then transfer to
freezer containers. (Defrost frozen cookies overnight in the refrigerator before baking.)
Using about 2 level tablespoons per cookie, shape dough into balls. Arrange 8 cookies on each pan, leaving about 2 inches between them, because the dough will spread. Bake for 12 minutes, or until the tops are no longer shiny, switching the position and rotating pans halfway through baking.
Cool cookies on the pans on cooling racks for about 2 minutes to firm up a bit, then transfer to the racks to cool completely. Repeat with second batch of cookies. The cookies can be stored in an airtight container for up to 2 days.
I used self-raising flour instead as it was available in the pantry and forgot to add the salt in. Also, I used only 1/2 cup of sugar instead of the 3/4 cup called for by the recipe. For the chocolate, I used Cadbury 70% and macadamia milk chocolate which turned out to be great as I love the nuts in the cookies.