Finely chop zucchini, carrot, and onion in a food processor. Scoop the mixture onto layered paper towels and squeeze out as much moisture as possible.
Add the vegetables to a large bowl along with ground turkey, parmesan cheese, eggs, oats, garlic powder, Italian seasoning, red pepper flakes, kosher salt and black pepper. Mix until well combined.
Add 2 jars marinara sauce into a large pot. Shape turkey mixture into approximately 44 medium-sized balls and carefully add each one to the pot of marinara sauce (it's okay if some are on top of each other and not submerged in the sauce). Without stirring, cover the pot and simmer 20 minutes. Uncover the pot, gently stir the meatballs so they are all covered in sauce, and simmer for an additional 20 minutes.
Serve over steamed greens or with whole grain spaghetti.