Preheat oven to 350°F (175°C) and grease a 12-cup standard muffin tin thoroughly with non-stick cooking spray.
Combine eggs, cottage cheese, salt, black pepper, and garlic powder in a high-speed blender.
Blend on high for 30 seconds until the mixture is completely smooth and slightly frothy.
Pour the egg mixture into a mixing bowl and fold in the shredded cheddar, parmesan, and chopped spinach.
Distribute the mixture evenly across the 12 muffin cups, filling each approximately 3/4 of the way to the top.
Bake for 22 to 25 minutes or until the egg bites have risen and the centers are firm to the touch.
Allow the bites to cool in the pan for 5 minutes to facilitate easy removal without tearing.
Use a thin spatula or knife to gently release the edges and lift the egg bites from the tin.