Preheat oven to 350 degrees. Line baking sheets with parchment paper or nonstick baking mats; set aside. Don't grease the baking sheets because this might cause extra spreading.
In the bowl of an electric mixer fitted with the paddle attachment, cream together butter and sugars. Add eggs, one at a time, mixing well after each addition. Reduce speed to low and add vanilla, then add both flours, baking powder, baking soda, salt and chocolate; mix until well combined.
Using a 4-ounce scoop for larger cookies or a 1-ounce scoop for smaller cookies, scoop cookie dough onto prepared baking sheets, about 2 inches apart. Bake until lightly browned, but still soft, about 20 minutes for larger cookies and about 15 minutes for smaller cookies. If you use a rounded tablespoon, check your cookies at 12 minutes. Cool slightly on baking sheets before transferring to a wire rack to cool completely.
If you use a very generously rounded tablespoon or a 1 scoop, you'll get about 4 dozen cookies.