Preheat oven to 350 degrees F. Line cupcake tin with cupcake liners. Place an Oreo in each cup.
Combine dry ingredients from flour - salt in a medium bowl.
Beat together butter with sugar until light and fluffy. Add eggs one at a time until incorporated. Add the vanilla and sour cream.
Add the flour and milk alternately, beginning and ending with the flour. Stir in the crushed Oreos. Fill each cupcake tin ¾ full. Bake for 18-20 minutes or until a toothpick inserted in the center comes out clean. Let cupcakes cool in the tin for 1 minute. Remove and cool completely on a wire rack.
While the cupcakes are baking, prepare the frosting. Place butter in a mixing bowl and beat until fluffy. Add the sugar, one cup at a time until incorporated. Add the crushed Oreos and 3 tablespoon of milk. Add additional tablespoon of milk until desired consistency. Transfer frosting to a piping bag.
Once the cupcakes have cooled, frost cupcakes. Serve.