Pour chili into small saucepan. Heat on low, stirring frequently until fully heated throughout. Keep chili warm until ready to use.
Whisk 1 cup cheddar, corn muffin mix, buttermilk, and egg together in a large bowl until smooth
Heat waffle iron until hot. Lightly coat the iron with butter, then, working in batches, add batter to waffle iron and cook until light golden-brown and fully cooked, about 4-6 minutes. Batter amount and cook time may vary; follow manufacturer instructions for best results. Repeat with remaining batter.
Top warm waffles with chili, remaining cheddar cheese, sour cream and scallions