Preheat oven to 450°.
Cut the cauliflower into small florets and place in a food processor, pulsing to "rice" the florets. (This may take 2 or 3 separate batches). Place in a microwave safe bowl and microwave 4 to 5 minutes to soften.
Place the cooked cauliflower onto a large, clean towel and let cool to the touch. Once cooled, Wring the towel over a sink to squeeze out as much moisture as possible.
Put the cauliflower into a large bowl and add the 2 cheeses, egg, and seasonings, and combine well with a spoon or spatula.
Spray a 13 by 18 inch baking sheet with cooking spray then place the dough on it and form a circle pressing with your hands. Press the dough to 1/4 inch thickness and a slightly raised rim. Place in the oven for 12 to 18 minutes, until the crust starts to brown.
Remove from the oven and top the pizza with the sauce, tomatoes and finally the cheese. Place the pizza back in the oven for 10 to 15 minutes, until the cheese begins to brown. Remove and add shredded fresh basil.