Preheat the oven to 425° and line 2 baking sheets with parchment paper. Set aside.
If using frozen riced cauliflower, prepare it according to the package and let it cool until it is cool enough to handle. If using fresh cauliflower, prepare a pot of boiling water. Cut the cauliflower into florets and place it in a steamer basket over the boiling water. Cover and steam for 5 minutes until the florets are fork-tender. Alternatively, the cauliflower can be steamed in the microwave in a microwave-safe bowl with a little water in the bottom for 5 minutes. Once cooked, place the steamed florets in a food processor and pulse for 10-15 seconds until you get a nice riced consistency.
Transfer the riced cauliflower to a tea towel or several layers of cheesecloth and squeeze to remove as much liquid as possible. There is more liquid than you’d think, I’m usually able to squeeze out nearly a cup of liquid. Measure out 4 cups of cauliflower and add to a large bowl.
Add the egg whites, 1 cup of mozzarella cheese, parmesan, Italian seasoning, garlic, salt, and pepper to the cauliflower and mix until fully combined.
Divide the mixture in half and add half to each prepared baking sheet in an even rectangle. Bake for 25 minutes, until the crust is nice and golden brown. Add the remaining mozzarella cheese and return to the oven to bake for another 5 minutes, until the cheese has melted.
Top with fresh herbs or a crack of black pepper. Slice into breadsticks and serve with marinara sauce or your dipping sauce of choice.