Preheat oven to 350 F. Place racks in the upper and lower thirds of the oven. Line two baking sheets with parchment paper.
Sift dry ingredients into a large bowl.
Add butter and sugars to the bowl of a standing mixer fitted with a paddle attachment. With the mixer on low speed, mix just until the butter and sugars are blended, about 2 minutes. Use a spatula to scrape down the sides of the bowl. Add the eggs one at a time, mixing until each is combined. Mix in the vanilla. Add the flour mixture to the bowl and blend on low speed until the flour is barely combined, about 30 seconds. Scrape down the sides and bottom of the bowl.
Add the chocolate all at once to the batter. Mix on low speed until the chocolate is evenly combined. Use a spatula to scrape down the sides and bottom of the bowl.
Scoop mounds of dough about 3 tablespoons in size onto the baking sheet, leaving 3 inches between them, or about 6 to a sheet.
Bake the cookies for 16 to 20 minutes, rotating the sheets halfway through, until the cookies are evenly dark brown. Transfer the cookies, still on the parchment, to the counter to cool, and repeat with the remaining dough. These cookies are best eaten warm from the oven or later the same day. They'll keep in an airtight container for up to 3 days.
This recipe is from Kim Boyce's 'Good to the Grain Baking with Whole-Grain Flours'