The brand was acquired by Leaf Brands last year, who have reportedly spent the time since attempting to bring back the cookie's original recipe rather than the reformulated version from when the cookies were made by Keebler and Kellogg's. According to Leaf Brands, they've gotten rid of high fructose corn syrup and hydrogenated oils.
The cookies are meant to feature a darker chocolate wafer, less sweet filling, and crunchier cookie when compared to Oreos.
Leaf Brands has partnered with Amazon for the initial roll-out of the cookies. The first batches of Hydrox to Amazon are slated to be delivered around the 15th of this month.
Hydrox were actually the first chocolate sandwich cookies I tried as a kid (mostly, because they used to go for 99 cents for a package, while Oreos were around $2). I don't recall them being very different from Oreos but, then again, that was a long time ago.