Preheat oven to 375 degrees and bring a large pot of salted water to a boil. Cook pasta to al dente and drain.
In a large pan, cook sausage, crumbling it with a wooden spoon as it cooks. Once no longer pink, remove it to a bowl with a slotted spoon and set aside.
Add onion, red pepper, and jalapeno to grease in pan and cook until softened, about 4 to 5 minutes.
Spoon onion mixture into bowl with 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 milk. Bring to a boil and simmer for 2 to 3 minutes, until thickened. Turn heat off and add 2/3 of the cheese. Stir until melted. Season to taste with salt and pepper.
Add pasta, and reserved sausage/onion mixture. Stir until evenly mixed. Pour into a buttered casserole dish or cast iron pan.
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.
Place in oven for 25 to 30 minutes.