Preheat oven to 400°F (200°C). Line a baking sheet with parchment paper.
Slice zucchini into ½-inch rounds (not too thin).
Season & pre-bake: Brush zucchini slices with olive oil. Sprinkle with salt, pepper, and garlic powder. Bake for 3–4 minutes to remove moisture.
Top with flavor: Spread a small amount of pizza sauce on each slice. Sprinkle mozzarella and Parmesan. Add one slice of pepperoni or your chosen topping.
Bake again for 8–10 minutes, until cheese melts and turns golden bubbly.
Serve warm with a sprinkle of oregano or Italian seasoning on top.