Preheat oven to 400 degrees F. Grease bottom of 13x9-inch baking dish.
Bring a large pot of water to boil. Scoop out zucchini seeds from each zucchini half (leave about ¼ inch around). Cook zucchini halves in boiling water for 1 minute. Remove and pat dry.
Place zucchini halves, cut side up, in prepared baking dish.
In a large skillet over medium-high heat, cook ground beef, stirring occasionally, until browned. Add onion, taco seasoning, black beans, corn, and diced tomatoes. Simmer for 2 minutes.
Scoop ground beef mixture into each zucchini boat. Sprinkle each boat with shredded cheese.
Bake in preheated oven until cheese is melted, about 30 minutes. Sprinkle with green onions, cilantro, and jalapeno rings (if desired). Enjoy!
Recipe by Simple, Sweet & Savory at https://www.simplesweetsavory.com/loaded-taco-zucchini-boats/