Preheat your air fryer to 350°F (175°C) for a few minutes.

In a bowl, crack the eggs and whisk them together until well beaten.

Add the sliced cherry tomatoes, sliced mushrooms, spinach, milk, ¾ cup of cheese, salt, pepper, onion powder and garlic powder to the bowl. Mix well to combine all the ingredients.

Grease a small round cake pan or a small baking dish that fits in your air fryer basket with cooking spray.

Pour the egg mixture into the greased pan.

Place the pan in the preheated air fryer basket.

Cook the frittata in the air fryer for about 12-15 minutes or until the eggs are set and the top is golden brown.

Sprinkle the ¼ cup shredded cheese over the cooked frittata and return it to the air fryer for another minute or until the cheese melts.

Carefully remove the frittata from the air fryer and let it cool for a few minutes.

Slice the frittata into wedges or squares and serve.