Preheat the oven to 350°F. Grease a muffin tin with cooking spray or olive oil.
In a large mixing bowl, whisk together the egg whites and cottage cheese until well combined.
Stir in the chopped spinach, diced bell pepper, shredded cheese, garlic powder, onion powder, salt, and pepper. Mix until evenly distributed.
Pour the egg mixture evenly into the prepared muffin tin, filling each cup about 3/4 full.
Bake in the preheated oven for 20-25 minutes, or until the egg bites are set and lightly golden on top.
Remove from the oven and let cool for a few minutes before carefully removing the bites from the muffin tin.
Serve warm or allow to cool completely before storing in an airtight container in the refrigerator.