Preheat the oven to 350 degrees F; line three baking sheets with parchment paper and lightly coat with cooking spray. Combine the all-purpose flour, whole wheat flour, salt and baking soda in a small bowl and set aside.
Combine the sugar, oil, milk, vanilla and egg white in a medium bowl and beat with a hand mixer on medium-high speed until smooth, about 1 minute. Add the flour mixture and beat on low speed until incorporated. Fold in the chocolate chips.
Drop teaspoonfuls of batter 2 inches apart on the prepared baking sheets. Bake for 7 minutes, remove the sheets and press the cookies down with a wooden spoon or the bottom of a measuring cup. Bake until golden brown, 4 to 5 minutes more. Let cool on the baking sheets for a few minutes, and then transfer to a rack to cool completely.