Preheat the oven to 500°F.
Remove the stems from the cauliflower and cut into small pieces. Then grate the florets with a cheese grater. You can also put them in a blender instead and pulse until the cauliflower has the consistency of rice.
Microwave the processed cauliflower in a microwave safe bowl on high for about 4 minutes. Take the cauliflower out of the microwave and then let it cool for at least 5 minutes. Transfer the cooled cauliflower to a kitchen towel and squeeze out all the liquid from the cauliflower.
Combine the cooked cauliflower, egg, garlic, 1/2 a cup of mozzarella cheese, parmesan cheese and seasonings. Stir until a dough forms. Spread the cauliflower mixture on lightly greased baking paper or in a pizza pan in the shape of a pizza crust. Place a second sheet of baking paper on top of the mixture and roll out with a rolling pin to make the crust extra crispy.
Bake the crust for about 10-15 minutes (depending on your oven) or until the crust is golden and crispy. Once the crust is golden, remove from the oven, spread with the marinara and top with the remaining mozzarella.
Place the pizza back in the oven, but this time turn on the broil function and bake for about 2-5 minutes until the cheese melts.
Slice and serve.
