Melt together cream cheese and butter in a small saucepan. Add crab meat and seasonings, stirring gently for 1-2 minutes. Remove from heat and cool to room temperature.
Spread mixture evenly over toasted muffin halves and sprinkle with chopped parsley and more Old Bay seasoning. Place on cookie sheet. (For OAMC, freeze them on the baking sheet, then transfer to a heavy duty freezer bag and use as needed). Bake in preheated 425F oven for about 5 minutes (about 10 minutes if frozen).
Serve whole, or use a pizza cutter and cut each into 4 segments for appetizers.