Melt the white chocolate in a double boiler or in a microwave safe dish.

Dip the bottom half of each Oreo into the white chocolate and set on a
piece of parchment paper.  Let harden for 10 minutes.  

Heat the green candy melts in a double broiler or in a microwave safe dish.  

Place in a zip top baggie.   Snip off the end.  Working quickly make a zig zag tree shape on a few Oreos and then sprinkle with the holiday sprinkles.  Place the gold or silver sprinkle on top.  

Repeat with remaining Oreos.

Allow to harden for 10 minutes then place in an air tight container.