Add the chopped bacon to a cold skillet, and turn the heat to medium. Cook bacon until crisp, about 8 to 10 minutes, and then remove the bacon, leaving the bacon fat in the pan.
Reduce heat to low, add the white parts of the scallions and celery to the pan, turn the heat to low, and slowly cook until soft and translucent, 5 to 10 minutes. Add the heavy cream and reserved oyster liquor and bring to a simmer. Allow the liquid to reduce until thickened, about 5 to 10 minutes. Stir in chopped oysters, bacon, and black pepper. Stir in salt and pepper, tasting and adding more if needed. Stir in green parts of the chopped scallions. Keep warm until ready to serve.
In a mixing bowl, combine the stuffing, egg, and baking powder. Using your hands, form the mixture into 4 round patties.
Coat a skillet with cooking spray, and heat on the stove over medium. Add the patties, working in batches if necessary, and cook until golden brown on both sides, about 4-5 minutes per side. Evenly distribute the oyster cream sauce over the four stuffin’ muffins, and serve immediately.
