In the mixing bowl of an electric blender, combine sugar, shortening, butter, vanilla and tofu. Add flour and salt until incorporated.
Form dough into 1" balls and roll in chopped nuts. Place about 1 inch apart on ungreased cookie sheet. Press thumb deeply in center of each. Bake about 10 minutes or until light brown. Immediately remove from cookie sheet to wire rack. Cool completely, about 30 minutes.