Audrey Piatti of Leonardo, New Jersey, shared this recipe with us. She writes, "I came up with this recipe because I could never decide what to do with all my zucchini...who knew these would be so good?"
Brown beef and onion in a skillet over medium heat; drain. Add spaghetti sauce to beef mixture and stir until combined. Meanwhile, lay zucchini halves, cut-side down, on a microwave-safe plate. Cook on high setting until fork-tender, about 5 to 10 minutes. Scoop out seeds and some surrounding pulp; discard. Sprinkle zucchini halves with salt and pepper; place in a greased 13"x9" baking pan. Spoon beef mixture into hollowed-out zucchini halves and top with cheeses. Bake, uncovered, at 350 degrees for about 40 minutes, or until heated through and cheese is bubbly. Serves 4.