Step 1: Preheat your oven to 400°F (200°C). Line a large baking sheet with parchment paper.
Step 2: If not using pre-riced cauliflower, cut the cauliflower into florets and pulse in a food processor until it resembles rice grains. Do not over-process.
Step 3: Cook the riced cauliflower: Microwave in a covered, microwave-safe bowl for 5-7 minutes until tender, or steam on the stovetop. Let cool slightly.
Step 4: Transfer the cooled riced cauliflower to a clean kitchen towel or several layers of cheesecloth. Squeeze out as much liquid as possible. This step is crucial for a crispy crust.
Step 5: In a large bowl, combine the thoroughly squeezed riced cauliflower with Parmesan cheese, egg, Italian seasoning, garlic powder, onion powder, salt, and black pepper. Mix well until a uniform mixture forms.
Step 6: Transfer the mixture to the prepared baking sheet. Using your hands or the back of a spoon, spread and press the mixture evenly into a round or rectangular crust, about 1/4 to 1/2 inch thick.
Step 7: Bake the crust for 20-25 minutes, or until the edges are golden brown and the crust is firm and somewhat crispy.
Step 8: Remove the crust from the oven. Spread with pizza sauce, then sprinkle with mozzarella cheese and your desired toppings.
Step 9: Return the topped pizza to the oven and bake for an additional 10-15 minutes, or until the cheese is melted and bubbly and the crust is golden brown and crispy.
Step 10: Let the Riced Cauliflower Crust Pizza cool for 5 minutes before slicing and serving. This helps the crust firm up even further.