Did Nabisco ever make a sandwich cookie with marshmello center?

There are a few reasons why this might be:

* Marshmallow's fragility: Marshmallows are notoriously delicate, and could easily get squished or become too gooey in a sandwich cookie format.

* Competing flavors: The combination of cookie and marshmallow might be a bit too sweet or overwhelming for some palates.

* Market competition: There are already a number of popular sandwich cookies on the market, with different fillings (chocolate, cream, etc.) that cater to a wide range of tastes.

It's certainly an interesting concept though! Perhaps one day Nabisco will experiment with this flavor combination.