Bake the pasta according to the package directions. Drain and rinse under cold water to stop the cooking process, set aside.
In a large cast iron skillet, over medium heat, cook the sausage-- breaking up as it cooks, until done. Drain, and set aside.
To the greasy skillet, add the onion and pepper, cooking until softened, about 4 to 5 minutes. Transfer the mixture to the reserved sausage.
Add the butter to the pan and melt over medium heat. Whisk in flour and cook for 2 minutes, stirring constantly. Gradually whisk in the milk. Bring the mixture to a boil and simmer for 2 to 3 minutes, or until thickened.
Remove the skillet from the heat and stir in roughly 2/3 of the cheese, stirring until it's melted and the mixture's smooth. Salt and pepper the sauce, to taste.
Stir in the cooked pasta, sausage, and veggies until everything's evenly incorporated.
In a medium bowl, whisk the eggs together and then stir in the remaining cheese plus the crumbled biscuits. Pour this mixture on top of the mac and cheese.
Bake at 375 degrees for 25 to 30 minutes.
Serve warm, with a drizzle of maple syrup, if desired.