Preheat the oven to 375°F and line a baking sheet with parchment paper.
Steam or microwave cauliflower until tender, then squeeze out excess water with a towel.
Mix cauliflower, spinach, eggs, cheese, garlic powder, onion powder, salt, and pepper in a bowl.
Scoop portions onto the baking sheet and press into small round shells.
Bake for 20 to 25 minutes until edges turn golden and shells hold together.
Cool slightly before lifting from the tray and filling with your favorite toppings.