Add the milk and butter to a microwave-safe measuring cup and microwave for about 90 seconds, until butter melted.
In a clean bowl, whisk together the flour, cornmeal, baking powder, sugar and salt.
Add the warm butter and milk mixture to the flour and cornmeal mixture and stir with a spatula until a smooth dough is formed.
Into the simmering soup, drop the dumplings by rounded scoops (about 1 1/2 tablespoons each) so they are evenly floating on top of the soup.
Reduce the heat to low, cover the soup pot with a lid and allow the dumplings to steam for 25 minutes. No peeking!
Serve the soup with sour cream and shredded cheese to top.