Towards the end, when Sofia's cake is done, she takes it out of the hot oven using potholders. Less than a minute later, when the men start to conga, you can see her discard the potholders and pick it up with her bare hands. It is a glass pan and still would have been much too hot to hold.
The exclamation point carving on the back of the front door was carved by Bea Arthur the first day on set. It can be seen throughout the show's entire seven seasons.