Preheat your oven to 450°F (230°C) and line a baking sheet with parchment paper.
Begin by ricing the cauliflower. You can do this by cutting the cauliflower into florets and pulsing them in a food processor until they resemble rice grains. Alternatively, you can grate the cauliflower using a box grater.
Transfer the riced cauliflower to a microwave-safe bowl and microwave on high for 5-7 minutes, or until softened. Let it cool slightly.
Once cooled, place the cauliflower in a clean kitchen towel or cheesecloth and squeeze out as much moisture as possible. This step is crucial for a crispy crust.
In a large mixing bowl, combine the drained cauliflower, egg, mozzarella cheese, Parmesan cheese, garlic powder, oregano, salt, black pepper, and red pepper flakes (if using). Mix until well combined.
Spread the cauliflower mixture onto the prepared baking sheet, shaping it into a round pizza crust about 1/4 inch thick.
Bake in the preheated oven for 12-15 minutes, or until the crust is golden brown and firm to the touch.
Remove the crust from the oven and add your favorite pizza toppings. Return to the oven and bake for an additional 5-10 minutes, or until the cheese is melted and bubbly.