The best option to edit the issues with verb voice and mood is:
An hour after Sheila placed the lasagna in the oven, we smelled a tantalizing aroma and our stomachs began to growl. "Take it out of the oven, and then you should cut everybody a slice," Cynthia said to Sheila.
This option corrects the verb voice by using an active voice ("we smelled") instead of the passive voice ("a tantalizing aroma was smelled"), making the sentence clearer and more direct. It also maintains the appropriate mood for the dialogue.