In a small bowl, combine the flour, pumpkin pie spice, and baking soda.
In a medium bowl with an electric mixer, cream butter and sugar. Beat in eggs, pumpkin and vanilla. Beat in the flour mixture until just combined. Stir in the white chocolate and pecans.
Drop the dough by rounded tablespoons 2 inches apart onto an ungreased cookie sheet. Bake for 20 to 22 minutes, or until just set. Transfer to wire racks to cool. Note: A friend said she cooked them at 350 degrees for 12-15 minutes to shorten baking time, but I haven't tested that temp/time combo yet.