Cook the bacon (or reheat) in a large skillet over medium heat until cooked and crispy. Place the bacon on paper towels to drain the grease, then chop it into bits.
Remove all but ½ teaspoon of bacon grease from the same skillet (or add ½ teaspoon butter), and add the spinach, minced garlic, crushed red pepper flakes, sea salt, and freshly cracked pepper to taste. Cook, stirring constantly, for 1-2 minutes, or until the spinach is wilted. Remove from the heat.
Fill a small skillet with enough water to about ¾ of the way up the side of the ramekin and heat over high until boiling.
Butter the ramekins well, then divide the wilted spinach and bacon crumbles evenly among the ramekins.
Add ½ teaspoon of heavy cream to each ramekin, then carefully crack one egg into each ramekin, not breaking the yolk. Run the edge of a rubber spatula through the egg whites a few times; be careful not to break the yolk. (This lets the egg whites to cook faster and more evenly.)
Once the water is boiling, turn off the heat, carefully add the egg-filled ramekins to the skillet, cover, turn the heat back up, and cook for about 6-8 minutes, or until the whites are set and the yolks are soft. Watch them carefully.
Turn off the heat and carefully remove the ramekins with tongs. Season with sea salt and freshly cracked pepper to taste, then serve immediately with buttered toast if desired. Enjoy.