How many Touhou characters can do the body split technique again? I know Suika and Flandre can, though through the use of different methods/powers.

Let's see... Suika, Flandre, Suwako, Mamizou... and if you count the spellcards as well, Youmu and Parsee.

Yuuka splitting herself in two is common.

Parsee can also make a clone of herself.