0 To a large bowl or the base of your stand mixer, add the oil, white sugar, and brown sugar. Using your stand mixer or electric hand mixer, start at a low speed and slowly increase it to high until the oil and sugar are fully combined. Scrape down the sides and bottom of the bowl.
1 Add the egg and vanilla to the bowl or stand mixer and mix until just combined. Scrape down the sides and bottom of the bowl as needed.
2 In a medium bowl, whisk together the flour, baking soda, salt, and cocoa powder.
3 If using a stand mixer, keep the mixer on while you slowly pour the dry ingredients into the wet ingredients. If using a hand mixer, add the dry ingredients into the wet, one cup at a time, mixing after each addition. Beat until just combined.
4 Fold the chocolate chips into the dough.
5 (optional) Cover the cookie dough and chill for at least 1 hour, up to overnight. We tested this recipe multiple times and found the cookies back up beautifully without chilling the dough, but if you're making ahead or having trouble with flat cookies, chilling is a great option.
6 When you’re ready to bake, remove the cookie dough from the fridge and allow it to soften for about 10 minutes. Note: if you’re only refrigerating your dough for an hour, you can skip this step – it should be soft enough to work with as is.
7 Preheat the oven to 350°F and line two baking sheets with parchment paper.
8 Using a #40 scoop, scoop the dough, then roll it in a ball with your hands to form the cookie balls. Place the cookies on the baking sheet, leaving 1.5 inches between each cookie.
9 Bake the cookies for 9 minutes. They are easy to overbake because they’re dark, but know that they’ll harden as they cool.
10 After about 5 minutes on the baking sheet, move the cookies to a wire rack to finish cooling before serving/storing.
