A full length tang that is in the shape of the handle desired.
2 slabs of wood roughly 2 - 2 1/4" wide and about 3/8" thick. Length will be just a little longer than handle. One trick also is to cut the excess material down near to the handle. It will be less you have to sand. Drill 2, 1/8" holes in handle. I would use a torch to temper the tang to a bluebird blue in order to get it soft for drilling. Make sure the pins, whether brass or steel fit the holes. You might need to sand them down a little or widen the holes.
After holes are drilled in tang, put handle material on one side and clamp. Drill the hole through the handle material using the holes in the tang as placement guides. Do the same to the opposite side.
Add adhesive to the tang. Then place the handle material on one side, run the pins through the tang and place handle material on the other side running the pins through it also. Clamp and let set up.
After it has set up, you will be able to shape the handle.