Line a rimmed baking sheet with parchment paper. Preheat oven to 425 degrees.
Grate the cauliflower using a box grater until you have 2 cups of cauliflower crumbles. Place in a large bowl and microwave for 7 to 8 minutes, or until soft. Remove from microwave and let cool.
Mix in the egg, 1 cup mozzarella, parmesan cheese, salt and pepper. Once combined, pat into a 10-inch round on the prepared pizza pan. Spray lightly with nonstick spray. Bake for 10-15 minutes, or until golden.
Top the pizza with 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.