Add the candy wafers to a double boiler (or use a small bowl and the microwave in short bursts). Melt the candy wafers until the perfect dipping consistency is achieved, add the vegetable shortening to help with the consistency of the dip.
Line a tray with wax paper, then dip each oreo cookie half way in the melted candy, to achieve the look of snow.
Lay on the wax paper, and repeat until all the cookies have been dipped.
Take the remaining melted candy and add the green food color. Transfer to a piping bag with a #1 tip and pipe the green tree part onto the cookies.
Add the brown sprinkles for the base of the tree and the other sprinkles to decorate the tree.
Notes
When adding the brown sprinkle, or the star on top of the tree I like to use a pair of tweezers. It can be quite delicate work and if you're like me, my fingers are not so delicate!Before dipping into the melted candy brush off any crumbs that may be on the cookie, so as not to dirty up the white.Use white chocolate if you prefer, instead of the melting wafers.