Preheat the oven to 425 F.

Line a sheet pan with parchment paper.

Cut the cauliflower into florets, discarding any large stem pieces. Place the florets into the bowl of a food processor and pulse until the cauliflower is chopped into small pieces that are about the same size as a grain of rice.

Place 4 cups of riced cauliflower in a large-sized microwavable bowl, and cover with plastic wrap.

Microwave for 10 minutes, or until the cauliflower is tender. When the cauliflower is done, remove the plastic wrap and let cool.

Add eggs, 2 cups of extra sharp cheddar and mozzarella, oregano, garlic, salt and pepper and stir to combine.

Divide the mixture in half and shape into 2 circles on the prepared baking sheet.

Bake for 25 minutes, then remove it from the oven and top with the remaining 1 cup of shredded mozzarella cheese and bake for another 5 minutes, until the cheese has melted and the edges are brown.

Serve with marinara sauce for dipping!