More to explore:
The Calumet Bakery does cupcake towers...
because a cupcake is just not enough. Doughnut on top of a coffee cake cupcake
Take 5 Cupcakes (pretzel, PB, Chocolate)
Sweet cupcake that we enjoyed at bring logo design studio while designing logos
This is from J-Lynne (Flutterby Cakes) She says It's done really easily by painting lines of colour inside the piping bag before piping.
more cupcake towers
Peanut Butter Cup Cupcakes Recipe on Yummly