• Preheat the oven to 350 degrees F and line a cupcake pan with paper liners.

For the Cupcakes:

• Cream together the butter and sugar with a hand held mixer or stand up mixer until light and creamy.  Then mix in the egg whites and vanilla extract.
• In a separate bowl, whisk together the dry ingredients: flour, baking powder, baking soda and salt.
• Then mix the dry ingredients into the butter mixture until just combined on low speed.
• Mix in the sour cream and whole milk.  Fold in the chopped Oreo cookies.
• Pour the cupcake batter into the cupcake liners, filling them until they are approximately 2/3 of the way full.
• Bake for 18-20 minutes until a toothpick comes out clean.
• Place them on a cooling rack and allow the cupcakes to cool completely before topping them with the frosting.

For the Frosting:

• Beat the butter in a large mixing bowl with a hand held mixer or stand up mixer until light and creamy.
• Add in the powdered sugar and vanilla extract.  Then add in the milk until the frosting is a consistency that you can pipe onto the cupcakes.
• Gently stir in the crushed Oreo cookies.
• Pipe the frosting into a swirl pattern onto each of the cupcakes and top with an Oreo Cookie.
• Allow the frosting to set fully and then the cupcakes are ready to serve and enjoy!