Preheat oven to 400, line cupcake pan with liners.

Crush whole oreos into small pieces. Set aside.

In a mixing bowl, combine butter and sugar with an electric mixer, 1-2 mins until fluffy. Add in egg whites, and mix with a spatula. Add in sour cream, milk, vanilla, lightly beat with a mixer,

In a separate bowl combine flour, baking soda, salt. Gradually add in flour mixture to the wet ingredients until thoroughly combined. Lastly add in crushed oreos. Mix until incorporated.

Fill cupcake liners ½- ¾ full.

Bake for 5 mins at 400, then lower temperature to 350 and bake for an additional 10 mins or until a toothpick once inserted comes out clean. ( cook times may vary based on ovens)

Crush oreos in a food processor as fine as you can make it.

Combine butter, shortening, and vanilla extract with an electric mixer. Once combined, gradually add in powdered sugar until it is the desired texture. Then add in finely blended oreos.