In a large bowl, combine chopped cookies, chocolate chips, flour and butter. Set aside. Mix cake per package directions. Pour 1/2 of the cake batter in pan. Sprinkle approximately 2 cups of the cookie mixture on top. Pour rest of cake batter over layer of cookies. Sprinkle remainder of cookie mixture on top.
Bake at 350 for 40-45 minutes, or until tested clean in the center.
In a small bowl, mix sugar with milk. Drizzle over warm cake.