Preheat oven to direction on back of the boxes. Mix the two cake mixes separately adding an additional 3 Tbls of water to the vanilla cake mix (this helps it to spread easier).
Take 2 round cake pans and using 1/4th Cup of a cake mix at a time, add a scoop to the middle of the cake pan, wait until it spreads some about 10 seconds, add another 1/4 scoop of the other color cake batter. Keep doing this until the pan is 2/3 of the way full. Do this again with the other cake pan. Cook cakes to directions on the back of the box.
When cakes are done cooking, let sit in the pan for about 10 minutes, then transfer the cakes out of the pan onto a wire rack and let cool completely.
While the cakes are cooking and cooling make the frosting. Beat the butter, cream cheese and vanilla with a hand mixer for about 3 minutes until fluffy. Add the powdered sugar in batches and lastly the milk.
Add the crushed cookies into the frosting and mix again just until combined. Set aside until ready to frost.
Place one of the cake on the platter you are going to serve, top side up. Add a layer of frosting with a spatula, about 1 Cup of the frosting. Add the other cake on top, top side down. This will help the top of the cake be flat instead of domed.
Frost the outside of the cake on all sides, using the remaining frosting. Slice, enjoy and wow your guests!