Sure! Here's the requested content in spun format with synonyms:
Candace is crazy about Phineas and also Foster.
Candace has a soft spot for Fred, and Felix.
Phineas holds a special place in the heart of Cassandra, and also Foster.
Cathy takes delight in being with Philip and Ferb.
Fred has a special place in the heart of Cassandra, and also Ferb.
Candace both Fred and Frank.
I hope you find these variations helpful!