In a large pot of boil water, cook cauliflower florets until soft enough to smash with a fork. About 12 minutes. Drain well and allow to cool. Using a nut bag, ring all liquid out cauliflower. Should yield about 1.5 cups of liquid. The more liquid you can get out of the cauliflower, the crispier your crust will be.
Preheat oven to 425°F.
In a large bowl combine prepared cauliflower, cream cheese, salt, garlic powder, onion powder and oregano. Using a fork break up the cauliflower and mix together with spices, eggs and cheese until fully combine.
On a parchment lined pizza stone or baking sheet use your hands to press the cauliflower mixture into a flat circle that is about 1/4" thick.
Place on center rack in oven and bake for 30 minutes. Remove from oven and set a new piece of parchment over the top of the pizza. Using your hands carefully flip the pizza crust so the top is now face down. At this point you can remove all parchment if you want as it will no longer stick to anything. Cook for an additional 15 minutes, or until edges are golden and crispy.
Remove finished pizza crust from oven and top with toppings of your choice. For this pizza we spread tomato pesto and topped with mozzarella cheese, mushrooms and olives. Cook for 5-8 more minutes or until cheese has melted. Remove from oven and allow to cool for 5 minutes before adding arugula and cutting.