I spent some time on the Internet looking up different examples to see if my idea was even feasible. Then I hit up Michael's to look for different pan options.
I didn't like any of the molds and I had it in my head that I really wanted to do a 3D cake. At Michael's I found small cake pans (6 inches maybe?) that would work.
I used a cake mix and cooked 4 different small cakes. I stacked 3 of them on top of each other (with frosting) in the middle and carved it into a ball shape. I wasn't sure about frosting it with all those crumbs, but I read about doing a "crumb coat" and tried it out. It worked!
As my crumb coat was setting (in the fridge) I started making the frosting colors.
I wasn't sure what I was going to do about the stem. In the middle of cake making, I still didn't know what to do. I saw an idea online to use an ice cream cone...but we didn't have one of those. But I looked over on the counter and saw a mini cupcake we had and I cut the top off and stuck it on top!
To make the jack-o-lantern face I stuck some large tootsie rolls in the microwave on medium power for 15 seconds and rolled them flat with a rolling pin. Then I stuck them on with frosting on the back of them!