Strawberry Christmas Tree Cupcakes - I would probably substitute the frosting with white chocolate tinted green... who doesn't like chocolate covered strawberries, plus that way, they would "stick" to the brownies.
Cupcake cake with owl pops in the tree. (This is a pic only but I suggest you use your own recipe for the cupcakes and then add green food coloring to the frosting for the leaves in the tree and chocolate frosting for the trunk of the tree. IT looks like there is also a few fondant leaves too. Make owl pops and stick them in randomly. There are lots of recipes for owl pops on Pinterest) Fun idea!