Preheat your oven to 400°F. Line a baking sheet with parchment paper.
In a food processor, pulse the cauliflower florets until they resemble rice or fine crumbs. Transfer the cauliflower to a clean kitchen towel and squeeze out as much moisture as possible.
In a large bowl, combine the drained cauliflower, mozzarella cheese, Parmesan cheese, eggs, garlic powder, onion powder, oregano, salt, and black pepper. Mix until well combined.
Using your hands, form the mixture into small, flat 'toast' shapes, about 1/2 inch thick, and place them on the prepared baking sheet.
Bake in the preheated oven for 20-25 minutes, or until the toasts are golden brown and firm to the touch.
Remove from the oven and let cool slightly. Garnish with chopped parsley if desired, and serve warm.