Preheat the oven to 400 degrees F. Line a baking sheet with parchment paper.
Pulse the cauliflower in a food processor until fine. Steam in a steamer basket for 4 to 5 minutes and drain well. (I like to put it on a towel to get all the moisture out and squeeze to dry.) Let cool.
In a bowl, combine the cauliflower with 1/2 cup of the mozzarella, the Parmesan, oregano, salt, garlic powder and eggs. Transfer to the center of the prepared baking sheet and spread into a circle, resembling a pizza crust. Bake for 20 minutes.
Add the marinara sauce, the remaining 1 cup mozzarella and more Parmesan if using and bake an additional 10 minutes.
Tear the basil over top of the pizza while still hot. Sprinkle with additional Parmesan if desired.