Preheat the oven to 375°F (190°C) and lightly grease a mini muffin pan.
Prepare the broccoli. Steam the broccoli florets until tender, then finely chop them and allow them to cool slightly.
Mix the ingredients. In a large mixing bowl, combine the chopped broccoli, cheddar cheese, Parmesan cheese, eggs, breadcrumbs, garlic powder, onion powder, salt, and black pepper. Stir until evenly mixed.
Fill the muffin pan. Scoop the mixture into the mini muffin tin cavities, pressing gently so the mixture holds its shape.
Bake the broccoli puffs. Place the muffin tin in the oven and bake for 15–18 minutes, or until the tops are golden brown.
Cool and serve. Let the puffs rest for about 5 minutes before removing them from the pan. Serve warm with your favorite dipping sauce.