Preheat the oven to 350 degrees F.

Lightly grease a large baking sheet.

In a medium bowl, beat together the sugar and butter.

Add the eggs and beat well.

Add the flour, baking powder, orange zest and salt to the mixing bowl and beat on low speed until combined.

Fold in the sweet potato, butterscotch chips and chopped pecans.

DIvide the dough into two equal pieces.

With oiled hands, shape each piece into logs about 2 inches by 11 inches.

Place both logs on the baking sheet.

Bake for 25 minutes or until firm and golden.

Let the logs rest on the baking sheet for 5 minutes, then transfer to a cooling rack and cool for 15 minutes.

Trim a thin slice from each end of the logs and set aside.

Cut logs into 1/2 inch thick slices.

Place the slices on the baking sheets.

Bake for 12 minutes; turn them over and bake until crisp, 10 minutes longer.

Cool completely.