Preheat the oven to 350° F. Line two baking sheets with silpats or parchment paper.
In a large mixing bowl on medium speed beat both sugars, the peanut butter, butter, salt, baking soda, corn starch and vanilla together about 2 minutes or until creamy and combined.
Beat in the egg.
Add the oats, flour and milk - beat on low until combined - if the mixture is too thick to beat mix by hand.
Stir in the chocolate chips.
Cover with plastic and refrigerate ½ hour or up to 24 hours.
Scoop up two tablespoons of the dough and roll into a ball. Place about 1 + ½ inches apart on the baking sheet.
Bake 9 - 12 minutes or until light brown on the bottom. Remove from the oven and press a few chocolate chips into the top of each one if you like.
Cool on the sheet 10 minutes then remove to a wire rack and cool completely.
Store tightly covered in a cool, dry place up to one week.