Pipe a swirl of the first kind of frosting onto cupcakes using a large round tip. I used Wilton tip number 1A , but if you don’t have a tip, you can just cut the end off of a sandwich bag.
Place the cupcakes in the freezer for 20 minutes or until the frosting is frozen solid.
Place chocolate chips and oil into a tall microwave-safe cup (I used a two cup Pyrex measuring cup).
Microwave for twenty seconds at a time (stirring in between) until all of the chocolate is melted.
Take the frosted cupcakes out of the freezer. One by one, grab the cupcakes by their wrappers, turn them upside-down, and dunk them into the cup of melted chocolate - making sure that all of the frosting gets covered. (If you listen carefully, you may be able to hear them squealing, “Wheeee!”) Let the cupcakes hover over the cup of chocolate until all of the excess chocolate drips off.
Admire your work.
Return the dipped cupcakes to the freezer for a few minutes until the chocolate has completely hardened.
Pipe the second frosting on top of the hardened chocolate using the round tip again. Don't make the swirl go all the way to the edge of the chocolate; if you do, you'll end up with more of a blob shape. I placed my swirl about 1/4" in from the edge.
Freeze the cupcakes with the second layer of frosting for another 20 minutes or until the frosting is frozen solid.
Dip the cupcake in the melted chocolate again (you will need to reheat your chocolate in the microwave for another 20 seconds or so and stir well). Dunk them all the way, covering both the new layer of frosting and the old layer of chocolate.