Grease a large 6-cup muffin tin or a 12-cup muffin tin and preheat the oven to 350°F.
In a large bowl, mix bread, most of the cheese, sausage, green onion, and mushrooms.
In a separate bowl, whisk eggs, cream, onion powder, salt, and pepper.
Pour egg mixture over bread mixture and fold together, pressing gently so the bread absorbs the liquid. Let sit for 10 minutes.
Spoon mixture into muffin tins, piling high and pressing down firmly.
Top with the remaining cheese, dividing between the muffins.
Drizzle each muffin lightly with maple syrup.
Bake for 45 minutes, until set and golden.
Serve warm or cool completely and store for later.
