Preheat the oven to 425 degrees F. Line 2 baking sheets with parchment paper.
Trim the leaves off the head of cauliflower. Cut it into small to medium florets.
Finely chop the cauliflower in a food processor until it resembles rice. You may have to do this in batches depending on capacity.
Spread the chopped cauliflower across one of the sheet pans. Bake for 15 minutes, stirring halfway through cooking. The cauliflower should be tender but not mushy and some of it will be lightly browned at the edges.
When the cauliflower is cool enough to handle, wrap it in a pouch with cheesecloth or a clean kitchen towel. Squeeze out as much moisture as you can.
In a large bowl, combine the cauliflower, egg, almond flour, Parmesan, mozzarella, oregano, garlic powder, salt and pepper. Stir together the ingredients until they are fully combined and come together in a rough dough.
On the other sheet pan, press the cauliflower mixture into a 10-12-inch diameter circle that is about 1/8-inch thick.
Bake the crust for 20-25 minutes until it is golden brown.
To assemble the pizza, spread on the sauce leaving a 1-inch border. Add the cheese and the rest of your desired toppings.
Switch the broiler on high and melt the cheese on the pizza. This will take 2-3 minutes. Watch the pizza, so it doesn’t brown too much under the broiler.
Drizzle the pizza with pesto and serve warm.