Bring a large pot of water to a boil. Cook pasta until just tender, 8 to 10 minutes or according to package directions. Drain.
Meanwhile, heat oil in a Dutch oven over medium heat. Add bacon and cook, stirring occasionally about 2 minutes. Add shrimp, bell pepper, garlic, Cajun seasoning and pepper. Cook stirring, until the bell pepper is beginning to soften, about 3-4 minutes. Cook shrimp until it is opaque.
Add tomatoes and their juice; bring to a simmer. Cook, stirring often, until the sauce is bubbling and reduce until thickened.
Remove from the heat and stir in Amazin Mayo.
Add chopped onions to a bowl and heat in microwave 2-3 minutes. You may add a little bit of water to help steam them. Once heated drain water.
Stir the pasta and onion into the sauce. Serve sprinkled with scallions, if desired.
Recipe and photo courtesy of eatingwell.com