Preheat the oven to 350°F (175°C) and liberally grease a 12-cup silicone muffin pan or standard muffin tin with cooking spray.

Combine the eggs, cottage cheese, salt, and pepper in a high-speed blender.

Process on high for 30 seconds until the mixture is completely smooth and no cottage cheese curds remain.

Pour the blended mixture into a mixing bowl and fold in the shredded cheddar cheese and chopped spinach.

Distribute the mixture evenly across the 12 muffin cups, filling each approximately 3/4 of the way to the top.

Place a baking dish filled with 1 inch of hot water on the bottom rack of the oven to create a steam environment.

Position the muffin tin on the middle rack and bake for 22 to 25 minutes until the eggs are set and slightly domed.

Remove from the oven and let rest for 5 minutes in the pan before using a silicone spatula to gently release the bites.