Crust: Place Shreddies and walnuts in food processor; pulse into fine crumbs. Drizzle with butter; pulse to blend. Transfer to 9-inch (23 cm) pie plate; press firmly into bottom and sides.
Bake at 350 degrees F (180 degrees C) for 10 min. Cool.
Filling: Beat eggs and sugar in large bowl. Whisk in cream. Add sweet potatoes, spices, lemon zest, and salt; whisk until blended. Pour into prepared pie shell.
Bake 40 to 45 min., or until set. Cool. Refrigerate several hours before slicing.