Preheat oven to 400 degrees F. Coat a 3-quart rectangular baking dish with nonstick cooking spray. Set aside.
In a large straight-sided skillet, cook ground beef and onion over medium-high heat until beef is browned and onions are tender. Drain any excess fat. Add undrained chili beans, tomato sauce and chili powder; stir to combine. Bring to boiling; reduce heat. Simmer, covered, for 5 minutes.
Add sausages to prepared baking dish and arrange in a single layer. Top with chili mixture. Sprinkle cheese over chili mixture. Drop spoonfuls of corn muffin batter atop the cheese layer. Bake 15 to 20 minutes or until corn muffin mounds are golden brown. Top with green onions before serving.