
Giorgio C. answered 12/05/20
Native Speaker from Northern Italy
There are several ways you can express non-romantic love between two people; here are two:
"Ti voglio un sacco di bene"
"Ti voglio tanto bene"
"Ti voglio un bene che non finisce mai" (as suggested in another answer) is not something that Italians would use. It is something you might read in a greeting/valentine's card, maybe.