Simple Italian Meatballs in Marinara Sauce

Ingredients (9)

• + 3 tablespoons ketchup add to pantry
• + 1 tablespoon milk add to pantry
• + 1 pound extra-lean ground beef add to pantry
• ✓ 1 egg
• + ¼ cup dried plain bread crumbs add to pantry
• + 1 teaspoon Greek seasoning add to pantry
• + 2 (20 ounce) jars marinara sauce, or more to taste add to pantry
• + 1 pinch white sugar add to pantry
• ✓ ¼ teaspoon cayenne pepper