In a large pot, combine the olive oil, garlic, dried oregano, dried basil, dried parsley, and red pepper flakes. Cook over medium-low heat, stirring occasionally, until the garlic is golden and caramelized, 8-10 minutes. Add the marinara sauce and season with salt and black pepper. Stir to combine.
Roll the sausage into tiny grape-size meatballs and place them in the sauce. Stir to combine. Partially cover the pot, reduce the heat to low, and cook for at least 1 hour, stirring every hour or so.
When ready to serve, bring a large pot of salted water to a boil. Cook the penne according to package directions until al dente. Drain and divide the hot pasta among plates, topping each with sauce, parmesan, and oregano.
For Instant Pot: In the instant pot, combine the olive oil, garlic, dried oregano, dried basil, dried parsley, and red pepper flakes. Set the instant pot to sauté and cook until the garlic is golden and caramelized, 5 minutes. Stir in the marinara sauce and season with salt and black pepper.
Roll the sausage into tiny grape-sized meatballs and place them in the sauce. Stir to combine. Cover and cook on high pressure for 20 minutes.
For Slow Cooker: In the slow cooker, combine the olive oil, garlic, dried oregano, dried basil, dried parsley, red pepper flakes, marinara sauce and season with salt and black pepper. Stir to combine. Roll the sausage into tiny grape-size meatballs and place them in the sauce. Stir to combine. Cover and cook on low for 6-8 hours.