Preheat your oven to 400°F (200°C). Line a baking sheet pan with parchment paper and set aside.
Add steamed cauliflower, breadcrumbs, parmesan cheese, garlic powder, onion powder, and egg into a large mixing bowl. Using a fork, mix until well combined putting some pressure into the cauliflower florets to break them up.
Using your hands, scoop about 1 to 2 tablespoons of cauliflower mixture to form a ball shape then flatten sides to make nugget-like shape.
Place the cauliflower nuggets on the prepared baking sheet in a single layer.
Spray the cauliflower nuggets with avocado oil spray or lightly drizzle with olive oil. Bake in the preheated oven for about 20-25 minutes or until the nuggets are golden brown and crispy, flipping them halfway through for even cooking.
Once the cauliflower nuggets are crispy and golden, remove them from the oven.