The crock pot (or slow cooker, as it is also known) is an electric pot commonly used for simmering. Cooking its contents at a low temperature over a long period of time, the crock pot is ideal because it requires minimal attention. It's a fairly popular countertop appliance for families or those too busy to slave over a hot stove making dinner.
According to HowStuffWorks, "The slow cooker, which is essentially an electric pot with a stoneware insert, can do what no oven or stovetop burner can: cook food at consistently low and even temperatures for what might be as long as 10 or 12 hours. Dinner cooks while you're out."
This handy trick takes full advantage of the crock pot's easy cooking process. Tossing old bread (in this case leftover hamburger buns) into the crock pot along with some sugar, cinnamon and milk, the pot does all the work. What you're left with is a batch of warm french toast, perfect for breakfast or brunch!