Preheat oven to 350°; position rack in the center of oven.
In a bowl, whisk the flour, cinnamon, baking soda, and salt together until ingredients are evenly distributed; set aside.
Soften the butter in a large bowl, using an electric mixer on medium speed, about 1 minute.
Add both sugars, and corn syrup; continue beating on medium speed about 2 more minutes until soft, light, and pale brown.
Beat in the egg, then the egg white, milk, and vanilla until smooth.
Turn off beaters; add the prepared flour mixture (in stages, if necessary) and beat on low speed just until incorporated.
Stir in the oats and chocolate chips with a wooden spoon until the chips are evenly distributed.
Drop by rounded tablespoons onto a large ungreased baking sheet, preferably nonstick, spacing cookies 2 inches apart.
Bake 6 minutes, rotate the baking sheet from front to back, continue baking for about 7 minutes, or until the cookies are lightly browned, somewhat soft, but definitely set.
Cool on the baking sheet for 1 minute; transfer to a wire rack to cool completely.
Cool the baking sheet for 5 minutes before baking another batch or use a second baking sheet that hasn’t been in the oven.
Storage: 5 days at room temperature; not recommended for freezing.
*Note: reduce the chocolate chips to 1 ½ cups and add 1 ½ cups of any of the following or a combination of the following—butterscotch chips, chopped pecans, chopped walnuts, dried cranberries, M&Ms, milk chocolate chips, peanut butter chips, raisins, Reese’s Pieces, roasted unsalted peanuts, sweetened shredded coconut, or white chocolate chips.