Preheat oven to 425°F. Line a baking sheet with parchment. Coat with the cooking spray.
Transfer the riced cauliflower & broccoli to a clean dish towel or cheesecloth. Squeeze out excess liquid. Add vegetables to a medium bowl, along with the eggs, mozzarella, and bread crumbs. Season well with salt and pepper and mix to combine.
By the tablespoon, scoop and form mixture into small nuggets and place on prepared baking sheet. Coat tops of tots with cooking spray. Bake 15 min., until browned and crispy.