Preheat your oven to 350°F (175°C).
In a bowl, mix together the Parmesan cheese, mozzarella cheese, egg, and onion powder until well combined.
Spread the mixture evenly on a baking sheet lined with parchment paper.
Bake in the preheated oven for 15 minutes or until golden and bubbly.
Remove from the oven and let cool slightly before cutting into pieces.
