1-3 Tablespoons egg white, or until dough comes together
1 teaspoon pure vanilla extract
5-6 Oreo cookies, crushed
Preheat oven to 375 degrees F. Line two or three baking sheets with parchment paper.
Whisk together flour, cornstarch, cream of tartar, and baking soda in a medium bowl.
With an electric mixer, beat together butter and sugar on medium speed just until smooth. Add egg white and vanilla.
Add flour mixture and stir until combined. Stir in Oreos. Refrigerate dough 10 minutes.
Using an ice cream scoop, distribute six evenly-spaced dough portions on one baking sheet. Bake for 10-12 minutes (I found 11 minutes to be about perfect, and keep in mind, they should be slightly underbaked). Let cookies cool on pan until set.
Repeat step 5 with remaining dough, refrigerating dough between each batch.