loading
Picture of Witches brew, creepy cauldron
Start by making a basic cupcake. Take off the cupcake case that it was baked in so that you just have the cake. 

Step 1: Naked cake

Picture of naked cake
Use a knife to coat the whole cake with a thin layer of buttercream, it doesn't have to be perfect, just coated enough that the icing with grip it. 
 
I love the way you made the "brew"!
Cute! What kind of frosting is that green frosting? The coloring is crazy :)