Here is the original item:
Hands covered in cookie dough,
(A) Madeline
ran to the phone,
(B) hoping
that the call was from Eric.
(C) Her boyfriend
who had broken his promise to call the day before.
You wanted to do this:
Hands covered in cookie dough, Madeline ran
to the phone hoping that the call was from
Eric. Her boyfriend who had broken his promise to call the day before.
Removing the comma after phone is an error. Hoping that the call was from Eric is a participle phrase. When such a phrase follows a main clause, you usually need a comma to connect the two parts.
You might want to review the rules.