Bubble Gum Rock is based on a kind of graffiti lettering that kids do. Each letter is a big fat outline that underlaps the one to its left.
To Create The Underlapping Effect, Type Your Sentences Like This Because The Caps Are Designed As Initial Letters And The Lowercase To Follow. This is a set of two fonts that work together. The Outline font contains pseudo brush-drawn outlines; the Fill font is the solid part that goes inside. In a program that allows layering, set the same bit of text in each of the two fonts, and position the Fill behind the Outline, and assign another color or percentage.