Preheat oven to 400degF.
Combine meatball ingredients in a large mixing bowl. Using a 1inch scoop, portion meat mixtures into balls. Roll between your hands to make round. Place on baking rack over a parchment paper covered baking sheet. Bake in oven for 30 minutes.
Start water boiling for the pasta.
In a frying pan over medium high heat, add bacon and cook until crispy. Remove to a paper towel covered plate. Reserve 2 tablespoons of bacon grease. Once bacon is slightly cool, chop into bits.
Add pasta to boiling water and cook as directed on the package. Drain in a colander and return to pot away from heat.
In a sauce pan over medium high heat, add reserved bacon grease, butter, onion powder and garlic powder. Once melted whisk in flour. Let cook for two minutes then whisk in milk and let cook for two minutes then whisk in seasonings and cook another two minutes. Whisk in heavy cream and cook another two minutes. Then add in cheese, a handful at a time, whisking until it's melted in.
Add cheese sauce to pasta, along with half of the bacon bits. and stir to thoroughly combine.
Add portion of mac & cheese to serving bowl. Add 6-8 meatballs and sprinkle with remaining bacon bits. Top with green onions.