Mix the flour, baking powder and salt with a sifter or whisk into a shallow bowl
Preheat the vegetable oil to 350 in a deep fryer or a deep pot large enough to cover the tails. If using a pot make sure the temp is stable before frying
Rinse the tails and trim the flippers off the bottom, then gently press and break the bottom cross ribs down the center to make them easier to butterfly
Turn them right side up and cut down the center with kitchen shears, then cut across the shell at the tail a half inch on each side. Open the shell from the top and gently dislodge the meat from the shell with your fingers but do not tear it completely out of the shell. Leave it attached at the tail end
Close the shell and rest the meat on top
Let the tail meat dangle and dip each tail in buttermilk, then shake off the excess
Dredge each tail in the flour mixture until completely coated and shake off the excess. Place the battered tails back on top of their shells
When the oil is at temperature, place the tails in a fry basket and deep fry for 4 minutes until golden brown, remove from oil and drain briefly
Serve immediately with the butter, honey mustard and sides