Preheat oven to 350 degrees F. Grease a 9×13 baking pan with non-stick spray. Set aside.
Prepare chocolate cake batter, according to package directions. Set aside.
In a separate bowl, mix together the (8 ounce) block of cream cheese, sugar and egg white. Beat together with an electric hand mixer, on medium speed, for 1-2 minutes or until combined and smooth.
Pour only half of the chocolate cake batter into the prepared 9×13 pan. Spread out evenly. Then take the cream cheese mixture and drop spoonfuls all over the batter in the pan. Take the back of the spoon and swirl the cream cheese mixture all over the top of the cake batter.
Pour the remaining cake batter all over the top of the cream cheese mixture. Carefully, spread the cake batter over the top evenly. Covering all of the cream cheese.
Bake for 38-40 minutes, or until a tooth-pick inserted in center of cake comes out clean. Let cake cool completely before frosting.
FOR FROSTING: In a bowl, combine the cream cheese and butter. Beat on medium speed until smooth. Gradually add in powdered sugar, then beat in vanilla and milk, until smooth. Spread frosting on cooled cake. Sprinkle the crushed candy canes all over the top.
Slice, serve and enjoy! ♥