Preheat oven to 400°F (200°C) and line a baking sheet with parchment paper.
Add cauliflower florets to a food processor and pulse until you get a rice-like texture.
Microwave the cauliflower rice for 5 minutes, then let it cool slightly. Place in a clean kitchen towel and squeeze out as much moisture as possible.
Transfer to a bowl and mix in Parmesan, mozzarella, salt, oregano, garlic powder, and egg until well combined.
Press the mixture onto the parchment-lined baking sheet into a crust shape, about 1/4-inch thick.
Bake for 20-25 minutes until golden and firm.
Add desired pizza toppings and return to the oven for an additional 10 minutes, or until cheese is melted.