Line a rimmed baking sheet with parchment paper, and preheat oven to 425ºF.
Grate the cauliflower using a box grater until you have two cups of cauliflower crumbles. Place in a large bowl and microwave for seven to eight minutes, or until soft. Remove from the microwave and let cool.
Mix in the egg, one cup mozzarella, parmesan cheese, and salt and pepper. Once combined, pat into a 10-inch round on the prepared pizza pan. Spray lightly with nonstick spray and bake for 10 to 15 minutes, or until golden.
Top the pizza with the sauce, 1/4 cup mozzarella, grape tomatoes, garlic, and red pepper flakes. Bake in the oven until melted and bubbly, another 10 minutes. Top with basil before serving.