Wash the zucchini, cut the ends off and then into half lengthwise to end up with 2 long pieces of zucchini. With a soup spoon remove the pulp from the center, leaving a border on each side and at each end of about 1/4 inch. Heavily salt the insides of the zucchini and place face down on a wire rack with paper towels underneath. If it’s not too seedy, salt the pulp of the zucchini and place next to the shells on the rack. Let sit for 30 minutes.
Heat a small sauce pan over medium heat and add in olive oil, onion, garlic and parsley. Cook about 3 minutes and when the onion is translucent, wring out the salted pulp in some paper towels and add to the pan. Cook for another 5 minutes or until the zucchini pulp is translucent and lightly sautéed, then turn the heat down to low. Start oven to 425 degrees F and set top rack to highest slot.
Stir the cream cheese into the vegetables, followed by the hard cheese shreds. Mix everything together until combined and you end up with a thick paste. Set aside.
Remove zucchini boats and wipe out with paper towels to remove leftover water and salt.
Start adding the cheese mixture into the zucchini, making sure to push down on the mixture as you add it. Transfer the stuffed zucchinis onto a baking tray lined with parchment paper, sprinkle the tops with some grated cheese and bake off at 425, 10-12 minutes or until bubbly and golden brown on top and the zucchini is tender.
Remove from the oven and let the stuffed zucchinis rest at room temperature for a couple of minutes so the stuffing can settle, sprinkle on some more parsley or cheese or paprika then CAREFULLY transfer to a serving dish and enjoy!