Spaghetti and Bean Balls with Arrabbiata Sauce

Name: Spaghetti and Bean Balls with Arrabbiata Sauce
Ingredients: 3 cup marinara sauce; ¼ teaspoon crushed red pepper flakes (or more to taste); 2 cup fully cooked and cooled red beans (small red beans such as aduki are ideal); 1 ½ cup fresh bread crumbs (stale is fine, but not toasted); 1 cup red onion (cut into ¼‑inch or smaller dice); 2 large eggs (lightly beaten); 2 tablespoon minced flat leaf parsley (plus more as garnish); ½ teaspoon kosher salt (or to taste, plus more for pasta water); ¼ cup canola oil (plus more as needed)