Preheat your oven to 400 degrees Fahrenheit. Line a large baking sheet with parchment paper or a silicone baking mat to prevent the cheese from sticking and to ensure an easy cleanup after your Christmas dinner is over.
Wash the zucchinis thoroughly and pat them dry with a towel. Slice them into rounds that are roughly a quarter-inch thick, trying your best to keep the thickness even so they all cook at the same rate.
In a medium mixing bowl, toss the zucchini slices with olive oil until they are well coated. In a separate small bowl, combine the grated Parmesan, garlic powder, dried oregano, salt, and black pepper. Dip each side of the oiled zucchini rounds into the cheese mixture, pressing gently to make sure the seasoning sticks.
Place the coated zucchini rounds in a single layer on the prepared baking sheet. Avoid overlapping them so that the heat can circulate around each piece, which helps them get crispy rather than steamed. Bake in the center rack of the oven for about 12 to 15 minutes, or until the zucchini is tender when pierced with a fork.
To get that perfect golden Christmas glow, turn your oven to the broil setting for the last 1 to 2 minutes of cooking. Watch them very closely during this time as the cheese can go from golden to burnt very quickly. Remove from the oven once the tops are bubbly and brown.
