1.Sift dry ingredients into a medium bowl. Season to taste. Make a well in the centre of the flour. Gradually whisk in combined buttermilk, egg and butter, until smooth. Set aside for 15 minutes.
2.Meanwhile, heat oil in a medium-sized, deep saucepan (test oil by dropping a small piece of bread into the oil. If it sizzles immediately, the oil is ready).
3.When oil is ready, dip 2-3 frankfurts into batter, draining off excess. Deep-fry for 2-3 minutes, turning, until golden. Drain on paper towel.
4.Thread each pluto pup onto a wooden skewer. Continue with remaining frankfurts and batter. Serve pluto pups with tomato sauce, for dipping.