Combine butter, cream cheese and powdered sugar in one bowl. In another bowl, combine pudding and milk, then add Cool Whip. Combine the 2 bowls. Layer serving bowl with 1/3 cookies, 1/2 filling, 1/3 cookies, 1/2 filling, and 1/3 cookies.
HINT: To crush Oreos, wrap plastic bag in towel and step on it. Kids love to help!