Preheat oven to 400° F. Rinse one large cauliflower head, cut off the stems, and toss them into a microwave safe bowl. Cover with plastic wrap and microwave for 10 minutes, or until cauliflower is fork-tender. Let cool slightly so that it is comfortable to handle.
In a thin kitchen towel place cauliflower in center and fold up all edges to meet in the middle in a big clump. Over the sink, gather and twist the edges together so that the liquid drains out of the cauliflower (try to keep your hands away from the hot liquid). Continue twisting until liquid is removed. Open towel.
Place cauliflower back into bowl. Make sure that mixture is slightly cool. Add one egg, ½ teaspoon dried oregano, ¼ teaspoon garlic powder, and ½ shredded mozzarella cheese. Stir to combine.
Line a baking pan with parchment paper and use fingers to flatten cauliflower into a thin crust. I flattened mine to about ½ inch thickness. Spray lightly with cooking spray or olive oil.
Place on the middle rack in preheated oven and bake for 50 minutes. Then turn the broiler on and broil for 5 minutes until top of crust begins to crisp up and turn golden color. Remove from oven.
Add tomato sauce, shredded cheese, parmesan cheese, and toppings. Place back into oven and broil on low for 4 minutes or until cheese is melted. Cut into squares and enjoy!
Recipe by at http://www.beautifullynutty.com/cauliflower-pizza-crust/