Preheat oven to 375 and grease a 9x9 glass baking dish. Set aside
Heat a large skillet over medium heat. Add olive oil and Italian Sausage to pan. Cook and crumble until no longer pink. Remove sausage from pan and set aside. Drain off fat from the pan.
Add riced cauliflower and Italian seasoning to pan. Saute over medium high heat until cooked through and the majority of liquid is cooked out. It will be crumbly!
Add cauliflower to prepared baking dish. Toss with 1/2 cup of mozzarella cheese. Spread cauliflower/cheese mixture in the bottom of the baking dish and press down with the back of a spatula creating a "crust".
Bake at 375 for 10 minutes.
Remove from oven. Top with pizza sauce, veggies, and crumbled sausage. Add the remainder of mozzarella cheese, and top with pepperoni slices.
Bake for another 15 to 20 minutes until the cheese is melted and bubbly.
Optional--Broil on high for 1 minute for a crispier cheese and pepperoni topping.
Cut into 9 equal squares and serve!
Notes
The toppings are all optional and up to personal preference. If you do not like sausage on your pizza, feel free to skip that step. You can also use already prepared sausage crumbles to save time.