How to Make It
Stir together the melted butter and crushed cookies in a medium bowl. Line the bottom and sides of a 9-inch square pan with foil, leaving a 2-inch overhang on all sides; lightly grease foil with cooking spray. Press the cookie mixture into the bottom of the prepared pan.
Beat the cream cheese, marshmallow cream, and vanilla in a large bowl with an electric mixer on medium speed until light and fluffy, 2 to 3 minutes. Gently fold in the coarsely crumbled cookies. Add the cream cheese mixture to the pan, spreading it evenly over the cookie crust. Cover and chill for at least 4 hours or up to 3 days. Lift mixture from the pan using the foil overhang as a handle, and cut into bars. Garnish with more coarsely crumbled cookies, if desired.