Preheat the oven to 450 degrees F. Line a baking sheet with parchment and coat with cooking spray.
Cook the frozen collards in a large bowl in the microwave according to package instructions. Let cool slightly.
Add the beef, black beans, Italian seasoning, garlic, egg, salt, and pepper to the collard greens. Mix with your hands until just combined. Mix with your hands until just combined. Scoop mounds of the meat mixture (about 2 tablespoons each) onto the prepared baking sheet. With damp hands, roll the mounds into balls and space them evenly apart on the baking sheet. Bake until completely cooked through, 12 to 14 minutes.
While meatballs cook, blanch the spiralized zucchini in boiling water to be al dente. Heat marinara over medium heat and add meatballs when done. Serve meatballs over spiralized zucchini.