Prep the oven: Heat to 300°F (150°C).
Place a rimmed baking sheet on the middle rack. Lightly spray a 12-cup muffin tin with nonstick spray.
Blend the base: In a blender, add eggs, egg whites, cottage cheese, mozzarella, Parmesan, salt, pepper, garlic powder, and onion powder. Blend until completely smooth and frothy, about 20–30 seconds.
Add mix-ins: Stir in bell pepper, spinach, and turkey bacon (if using).
Do not blend the vegetables; folding keeps texture and color.
Prepare the water bath: Place the empty muffin tin on the preheated baking sheet. Carefully pour hot water onto the baking sheet until it reaches about halfway up the sides of the muffin tin.
Fill the cups: Divide the egg mixture evenly among the 12 muffin cups, filling each about 3/4 full.
Bake gently: Bake for 22–28 minutes, until the centers are just set and slightly jiggly. Avoid browning.
If your oven runs hot, start checking at 20 minutes.
Cool briefly: Remove the muffin tin from the water bath and let the bites sit for 5 minutes. Run a thin knife around the edges to release.
Serve or store: Enjoy warm, or cool completely on a rack before refrigerating.