Preheat oven to 400 degrees F (200 degrees C). In a medium mixing bowl, combine pecans, flour, and butter. Press into a 9x13 inch pan. Bake for 25 minutes. Allow to cool.
In a large bowl, beat together cream cheese and confectioners' sugar until smooth. Fold in half of the whipped topping. Spread on top of cooled crust.
In a large bowl, combine milk, chocolate pudding mix, and vanilla pudding mix. Beat until thick. Pour over cream cheese layer. Top with remaining whipped topping, and sprinkle with crushed chocolate bars.