Preheat your oven to 425°F (220°C).
If using frozen cauliflower rice, thaw it according to the package instructions. If using fresh cauliflower, cut it into florets and pulse in a food processor until you get rice-like grains.
Place the cauliflower rice in a microwave-safe bowl and microwave on high for 4-5 minutes until it becomes soft. Allow it to cool slightly.
Once the cauliflower has cooled, transfer it to a clean kitchen towel or cheesecloth. Squeeze out as much moisture as possible. This step is crucial to achieving a crispy crust.
In a mixing bowl, combine the drained cauliflower, 1/2 cup shredded mozzarella cheese, beaten egg, dried oregano, garlic powder, and salt. Mix well to form a dough-like consistency.
Place a piece of parchment paper on a baking sheet or pizza stone. Spread the cauliflower dough on the parchment paper, shaping it into a 1/4-inch thick round crust.
Bake the cauliflower crust in the preheated oven for 15-18 minutes or until it turns golden brown.
Remove the crust from the oven and let it cool slightly. Increase the oven temperature to 450°F (230°C).
Once the crust has cooled a bit, spread the low-carb pizza sauce over it, leaving a small border around the edges for the crust.
Sprinkle 1/4 cup shredded mozzarella cheese over the sauce, and add your desired low-carb pizza toppings.
Place the pizza back in the oven and bake for an additional 5-7 minutes, or until the cheese is melted and bubbly.
Remove the pizza from the oven, let it cool for a minute or two, then slice and enjoy your delicious low-carb cauliflower crust pizza!