3/4 cup (1 1/2 sticks) unsalted butter, softened
3/4 cup brown sugar, packed
1/4 cup granulated sugar
1 large egg
2 teaspoons vanilla extract
1 cup all-purpose flour
1 cup bread flour (all-purpose flour may be substituted and used exclusively in place of bread flour)
2 teaspoons cornstarch
1 teaspoon baking soda
1/2 teaspoon salt, optional and to taste
6 ounces (3/4 cup) semi-sweet or milk chocolate chips
6 ounces bittersweet or dark baking chocolate, chopped into bite-sized chunks
- To the bowl of a stand mixer fitted with the paddle attachment, beat the butter on low speed until smooth, 1 to 2 minutes.
- Add the sugars and beat on medium-high speed until creamed and well combined, about 3 minutes. Stop, scrape down the sides of the bowl, and add the egg, vanilla, and beat on medium-high speed until light and fluffy, about 3 minutes.
- Stop, scrape down the sides of the bowl, and add the flours (solely using all-purpose flour will work, but the cookies will not be as chewy), corn starch, baking soda, salt, and mix until just combined, about 1 minute. Add the chocolate chips and chunks, and either fold in by hand or beat for a few seconds on low speed. Transfer dough to an airtight container and refrigerate for at least 30 minutes, up to 5 days (although chilling the dough is theoretically not necessary; in reality cookies spread less with chilled dough).
- Preheat oven to 350F, line a baking sheet with parchment paper. Using a 2-ounce cookie scoop or a 1/4 cup measuring cup, form heaping mounds and place them on the baking sheet, spaced at least 2 inches apart. Bake for 8 to 10 minutes, until barely golden brown around the edges, even if slightly undercooked in the center, noting the tops will not be browned and will be pale. Do not cook longer than ten minutes as cookies will darken and firm up as they cool. Allow cookies to cool on the baking sheet for 5 minutes before removing and transferring to a rack to finish cooling. Store cookies in an airtight container at room temperature for up to 5 days or in the freezer for up to 3 months. Alternatively, unbaked cookie dough can be stored in an airtight container in the refrigerator for up to 5 days, so consider baking only as many cookies as desired and save the remaining dough to be baked in the future when desired.