Start by lining a couple of baking sheets (or your kitchen counter) with parchment paper. This will be the "forest floor" for your trees to set.
Lay out your mini pretzel sticks on the parchment, leaving about 3-4 inches between each stick. These are going to be the trunks of your trees.
Add the olive oil to your white chocolate wafers and pour the mixture into a piping bag. Place the bag in the microwave and heat in 30-second intervals, massaging the bag between each round, until the chocolate is fully melted.
Once the chocolate is melted and smooth, snip off a tiny bit from the end of the piping bag. Now, here comes the fun part! In a zigzag, back-and-forth motion, pipe the white chocolate over the pretzel sticks. Start narrow at the top to mimic the point of a Christmas tree, and widen as you move down, leaving about an inch of the pretzel stick exposed at the bottom for the “tree trunk.”
While the chocolate is still soft, sprinkle your red, green, and white nonpareils generously over the “branches.” This is where kids can really get involved—it’s like decorating a mini Christmas tree but without the mess of pine needles!
Once you've piped all your trees and decorated them with sprinkles, let the chocolate harden for about 20 minutes. If you're in a hurry, you can pop the tray into the fridge to speed up the process.