Preheat oven to 300 degrees Fahrenheit (150 degrees Celsius) and place a baking pan filled with one inch of water on the bottom rack to create a steam environment.
Combine liquid egg whites, cottage cheese, salt, pepper, and garlic powder in a high-speed blender.
Process on medium speed for 20 seconds until the mixture is completely homogeneous and slightly aerated.
Lightly coat a silicone muffin tin with non-stick cooking spray.
Distribute chopped spinach, diced red peppers, and shredded cheese evenly across 12 muffin wells.
Pour the blended egg white mixture into each well until approximately 3/4 full.
Place the muffin tin on the center oven rack directly above the water pan.
Bake for 30 minutes or until the internal temperature reaches 160 degrees Fahrenheit and the centers are set.
Remove from oven and allow the bites to rest for 5 minutes in the silicone mold before extracting.