Adjust oven racks to upper middle and lower middle positions and heat oven to 375. Line 2 rimmed baking sheets with parchment paper. Whisk flour, salt, and baking soda together in a bowl.
Bring dates, butter, brown sugar, and orange zest and juice to simmer in a saucepan and cook until the mixture is slightly thickened and measures 2 cups, about 5 minutes. Transfer mixture to a large bowl and let cool to room temperature, about 30 minutes.
Whisk eggs into cooled date mixture, one at a time, until combined. Fold in flour mixture until just combined, then fold in butterscotch chips and pecans. Drop generous tablespoon size portions of dough onto prepared cookie sheets, spaced about 2 inches apart.
Bake cookies until edges are set and beginning to brown but centers are still soft and puffy, about 10 minutes, switching and rotating baking sheets halfway through baking time.
Let cookies cool on the cookie sheets for 10 minutes and then transfer to a wire rack and let cool completely. Repeat with the remaining dough using cooled, freshly lined baking sheets.
Lightly dust the COOLED cookies with confectioner's sugar before serving.