Chop all Oreo cookies into crumbs and combine with melted butter. Press mixture into a greased 9x13 baking pan.

Sprinkle all chocolate chips over the cookie layer. Then top with marshmallows and pecan pieces.

Drizzle sweetened condensed milk over top. Place uncovered in the oven for 20-25 at 350°, or until bubbling. Cool completely before cutting.