Make cake batter according to package directions and add in the sprinkles - mix well to combine.  

Allow the cupcakes to cool completely.  Then use a large round tip to frost the cupcakes with the white frosting.

Line 2 baking sheets with parchment paper and place 12 pretzel sticks on each pan.

Melt the green candy melts according to package directions and place the melted chocolate into a squeeze bottle or a ziplock bag with a small hole cut in the corner.  

Drizzle the melted chocolate over the pretzels in the shape of a tree, then sprinkle with the nonpareils.  

Allow to cool and harden completely before removing the trees from the parchment paper and placing into the frosted cupcakes.