4 tablespoons unsalted butter, at room temperature
2 teaspoons vanilla extract
1. Whisk white whole-wheat flour, all-purpose flour, cocoa, baking powder, baking soda and salt in a medium bowl.
2. Place 1/4 cup chocolate chips in a small, heatproof bowl; microwave on Medium for 1 minute. Stir, then continue microwaving on Medium, stirring every 20 seconds, until melted. (Or place chocolate in the top of a double boiler over hot, but not boiling, water. Stir until melted.) Let cool slightly.
3. Beat sugar, oil and butter in a mixing bowl with an electric mixer on high until smooth, scraping down the sides. Add eggs, vanilla and the melted chocolate; beat until smooth, scraping down the sides. Add the flour mixture and mix on low speed until just combined. Stir in the remaining 3/4 cup chocolate chips.
4. Place half the dough on a large piece of plastic wrap and shape into a 10-inch log (it’s OK if it’s not perfectly round). Repeat with the remaining dough. Wrap and freeze until just firm, about 45 minutes. Reroll the logs to make them rounder and return to the freezer until very firm, at least 1 hour more.
5. Preheat oven to 350°F. Line a baking sheet with parchment paper or a silicone mat.
6. Remove one roll of dough at a time from the freezer and let stand at room temperature for 5 minutes. Unwrap the dough and slice crosswise into 1/4-inch-thick rounds, turning the dough a quarter turn after each slice to help keep the cookies round. Place 1/2 inch apart on the prepared baking sheet. If your cookies aren’t as round as you want them to be, shape the dough with your fingers.
7. Bake 8 minutes for soft cookies or 10 minutes for crisp cookies. Transfer to a wire rack to cool completely. Repeat with the remaining roll of dough, if desired.
Tip: White whole-wheat flour, made from a special variety of white wheat, is light in color and flavor but has the same nutritional properties as regular whole-wheat flour. It is available at large supermarkets and natural-foods stores and online at bobsredmill.com or kingarthurflour.com. Store it in the freezer.
To Make Ahead: Store wrapped rolls of dough in the freezer for up to 3 months.