Grease a 9x13 baking dish with cooking spray and spread 1 cup of marinara sauce on the bottom of the dish; set aside.
Cut the zucchini in half, lengthwise, and scoop out the flesh with the tip of a spoon. Arrange the zucchini boats in the baking dish, flesh-side UP; sprinkle salt over each boat and set aside.
Prepare the Taco Beef mixture.
Once you've cooked the beef, wipe down the zucchini boats with paper towels. Fill the boats with the prepared beef mixture—no specific amount – just spoon in what the zucchini will hold.
Top each zucchini boat with remaining marinara sauce and add cheese on top.
Bake for 25 minutes or until the zucchini is tender and the mixture is bubbly.
Remove from oven and let stand a few minutes.
Garnish with parsley and serve.
Notes
Zucchini: Use medium-sized, firm zucchini.
Hollowing: Scoop zucchini flesh with a spoon, leaving a 1/4-inch border to retain shape during baking.
Repurpose Zucchini Flesh: Dice and add scooped-out flesh to the beef mix for enhanced flavor and nutrition.
Alternative Fillings: Swap taco beef with leftover meat sauce, chili, cooked chicken, pork sausage, etc., for variation.
Uniform Cooking: Use zucchini boats that are similar in size for even cooking. Larger ones may need extra baking time.
Prep Ahead: Assemble zucchini boats in advance, refrigerate, and bake when ready — perfect for meal prep or hosting.