Preheat the oven to 350°F (175°C) and grease a muffin tin with non-stick cooking spray.
In a mixing bowl, whisk the eggs and heavy cream together until smooth.
Add the chopped spinach, diced bell peppers, shredded cheddar cheese, chopped fresh chives, salt, black pepper, and crumbled bacon to the bowl. Mix until well combined.
Pour the egg mixture into the muffin tin, filling each muffin cup about 3/4 of the way full.
Bake for 18-20 minutes or until the egg muffins are set and golden brown on top.
Remove from the oven and allow to cool for a few minutes before serving. These can be stored in an airtight container in the fridge for up to 5 days.