01 - Preheat the oven to 375°F.
02 - In a 10-inch ovenproof skillet over medium heat, cook chopped bacon until crisp. Remove bacon with a slotted spoon and set aside, leaving about 1 tablespoon fat in the skillet.
03 - Add olive oil to the skillet. Sauté mushrooms, bell pepper, and green onions for 3 to 4 minutes until softened. Stir in spinach and cook until wilted, about 1 minute.
04 - In a large bowl, whisk together eggs, heavy cream, garlic powder, salt, and black pepper. Stir in shredded cheddar and grated Parmesan cheeses.
05 - Return cooked bacon to the skillet with the vegetables and spread evenly. Pour the egg mixture over the vegetables and bacon, gently stirring to distribute evenly.
06 - Cook the mixture on the stovetop for 2 to 3 minutes until the edges begin to set.
07 - Transfer the skillet to the preheated oven and bake for 15 to 18 minutes until the center is just set and lightly golden.
08 - Remove from the oven, let cool for 5 minutes, then slice and serve.