Preheat oven to 325 degrees. Spray bundt pan with Crisco and flour the pan.
In a mixing bowl, beat together cake mix, water, sour cream, egg whites, and vegetable oil.
Pour half of the batter into the pan. Sprinkle with crushed Oreos, trying not to touch the sides of the pan. Spread remaining batter evenly on top.
Bake 50-55 minutes until toothpick inserted near center comes out clean. Cool in pan 10 minutes.
Loosen cake from sides (I use a butter knife) and invert onto a plate. Cool completely.
For icing, beat together powdered sugar, sour cream, and butter in a small bowl until well blended. Ice top of cake evenly, allowing some to flow down sides.
Sprinkle with cookies. Store leftovers, covered, in refrigerator.
Recipe by Simple, Sweet & Savory at https://www.simplesweetsavory.com/cookies-and-cream-bundt-cake/