Bring a kettle of water to a boil. Preheat the oven to 300°F and set one oven rack in the middle position and another in the lowest position.

Place a 9x13-inch metal or ceramic baking dish on the lower rack and fill it halfway with the boiling water from the kettle. This will create steam in the oven, which will help the egg bites to cook gently and attain a custardy texture.

Spray a nonstick muffin pan generously with nonstick cooking spray.

In a blender, combine the eggs, cottage cheese, Gruyère, cornstarch, salt, pepper, and hot sauce. Blend until completely smooth, about 30 seconds.

Pour the egg mixture evenly into the prepared muffin pan, filling each well about three-quarters full. Sprinkle the spinach and scallions evenly over the batter. Use a spoon to press the greens into the batter so they are not all floating on top.

Bake for 20 to 25 minutes on the middle rack, until the eggs are set. You'll know they are done when the egg bites start to pull away slightly from the edges. Some of the egg bites may also puff up and look a bit lopsided, but they will settle and deflate as they cool.

Remove the egg bites from the oven and let rest in the pan for about 5 minutes. Use a small spoon to loosen the egg bites from the edges of the pan and carefully lift them out onto a plate. Serve warm.