Cut day-old bread into cubes and spread on a baking sheet. Toast in oven at 350°F for about 10 minutes if desired.

Cook sausage or bacon in a skillet over medium heat until crispy, about 5-7 minutes. Remove and drain on a paper towel. Sauté onion and bell peppers in the same skillet for 3-5 minutes.

In a bowl, whisk together eggs, milk, salt, and pepper until frothy. Stir in maple syrup or honey if using.

Combine toasted bread, cooked sausage or bacon, sautéed vegetables, and cheese with the egg mixture. Fold gently to coat the bread.

Grease a bundt pan and transfer the mixture into it, pressing down lightly.

Bake in a preheated oven at 350°F for 45-50 minutes until golden brown and set. Check doneness with a toothpick.

Let cool in the pan for 10 minutes, then invert onto a platter, slice, and serve warm.