3/4 cup dark brown sugar
1/4 cup granulated sugar
1 large egg
2 teaspoons vanilla extract
2 cups (250 grams) all-purpose flour
2 teaspoons cornstarch
1 teaspoon baking soda
1/2 teaspoon salt
1/2 cup semisweet chocolate chips
1/2 cup white chocolate chips
1/2 cup mini M&Ms (or other add-in of your choice)
- In a large bowl using a hand-held mixer or stand mixer with paddle attachment, beat the butter for 1 minute on medium speed until completely smooth and creamy. Add the brown sugar and granulated sugar and mix on medium speed until fluffy and light in color. Mix in egg and vanilla. Scrape down the sides and bottom of the bowl as needed.
- In a separate bowl, combine flour, cornstarch, baking soda and salt. On low speed, slowly mix into the wet ingredients until combined. The cookie dough will be quite thick. Add the chocolate chips, white chocolate chips, and M&Ms or other add-ins and mix for about 5 seconds until evenly disbursed. Scoop dough into golf-ball-size balls. Chill or freeze for at least an hour or up to 2 days.
- Preheat oven to 350 degrees F. Line a large baking sheet with parchment paper or a silicone baking mat.
- Place dough balls evenly spaced apart on baking sheet and bake for 8-9 minutes, until barely golden brown around the edges. They will look extremely soft when you remove them from the oven. Allow to cool for 5 minutes on the cookie sheet. Transfer to cooling rack to cool completely.