Take a look at the item again:
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 present 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.
Go back to the sentence to try again.