Preheat oven to 350 degrees F. Add papers to a cupcake baking sheet. Roughly chop enough Oreos to end up with about a cup.
Sift the flour, sugar, salt, baking soda and baking powder together in a large bowl then set aside.
In a medium bowl mix the egg whites, sour cream, milk and vanilla extract.
Cream the butter in a stand mixer fitted with a paddle attachment, or a large bowl if using an electric hand mixer.
Beat the dry ingredients into the butter until well incorporated, scrape the bowl at least once. You'll end up with a crumbly mixture.
Add the wet mixture to the butter/flour mixture and mix on low until just combined.
Fold in the chopped Oreos and mix until distributed.
Divide the mixture evenly into cupcake papers using an ice cream scooper.
Bake for about 15-20 minutes or until slightly golden at the edge and springy in the middle.