Pumpkin Squares

1 package yellow cake mix
1 can evaporated milk
1 1/2 cups sugar
1/2 teaspoon salt
1 cup butter
1 can (15 oz.) pumpkin
3 eggs
1 teaspoon cinnamon
1/2 cup chopped nuts
Cool Whip

Combine milk, sugar, salt, pumpkin, eggs, cinnamon and Cool Whip in a medium bowl. Sprinkle cake mix over mixture, then pecans, then melted butter. Bake at 350˚ for 50-55 minutes.