Using a sharp knife, carefully remove the center of the mini loaves to create a bowl. Remove additional bread from the inside by hand. Butter the inside of the loaves with the soft butter. Set aside.
Using the tops of the loaves and bread removed from center, cut into small cubes.
In a large mixing bowl, stir together onion, celery, parsley, melted butter, beaten egg, ground sage and red pepper flakes. Add cubed bread, salt and pepper then fold together to evenly distribute the mixture.
Slowly drizzle milk over stuffing mixture while stirring until bread cubes are moist but not soggy. (May need a bit more or less milk).
Spoon stuffing into individual bread bowls and set on a foil-lined baking sheet. Bake at 350 degrees F for about 45 minutes or until bread cubes on top are crispy.
While the stuffing bakes, make crispy sage leaves. Heat oil in a small skillet over medium-high heat until hot. Fry 6 sage leaves at a time until crisp, about 15 seconds. Transfer with a fork to paper towels. Set aside.
Remove stuffing from oven and garnish with chopped parsley and crispy sage leaves.